Fire Signal Butterfly Valve | DN50-400 Supervisory Switch Factory

A Fire Signal Butterfly Valve is a specialized fire-protection valve that integrates a butterfly valve's efficient on-off performance with an intelligent signal feedback (supervisory switch) function - a circular disc rotates 90° to open/close fire water flow, and high-precision travel switches + linkage mechanism convert the valve's real-time open/close/intermediate status into electrical signals (NO/NC switch signals, or optional 4-20mA analog via encoder) and transmit them to the fire control room/center for remote visual monitoring and automatic alarm - if the valve is accidentally closed, blocked, or fails, the signal change triggers an alarm in time to avoid fire safety hazards - with fast operation (manual ≤3s, electric 1-5s), compact structure (body length only 1/3-1/2 of same-DN gate valve, light, for narrow spaces), straight-through low flow resistance (ensures sprinkler/hydrant pressure/flow), EPDM/NBR/PTFE/Viton soft seat bidirectional zero leakage, 8-12 year service life, flange/wafer/groove connection, manual (handle/worm gear)/electric/pneumatic/electro-hydraulic drive, DN50-400 (2"-16"), PN10/16/25, -10~80°C, fire red coating, GB/T 5135.6-2018 fire signal butterfly valve standard - a reliable, code-compliant, supervisory-signal butterfly valve for fire protection water systems. The core highlights are: (a) Fire protection specialized: designed specifically for fire water supply systems (not general industrial) - meets GB/T 5135.6-2018 (Chinese national standard for fire signal butterfly valves), fire red coating, fire water media (-10~80°C), reliable for fire emergency; (b) Signal feedback (supervisory switch): the key differentiator from ordinary butterfly valves - high-precision travel switches (micro switches) + mechanical linkage with valve stem/disc - when disc reaches fully open, fully closed, or intermediate positions, switches activate and output electrical signals (NO/NC - normally open/normally closed contacts) to fire alarm control panel (FACP); optional encoder outputs 4-20mA analog for precise position/remote visual monitoring on SCADA/BMS; (c) Remote monitoring + alarm: fire control room can remotely see valve status (open/closed) without manual site inspection - critical for fire safety (ordinary valves require manual check, easy to miss); if valve accidentally closed (e.g., someone turns it, maintenance forgot to reopen), blocked (debris), or fails, signal changes → alarm triggers (buzzer/indicator on FACP) - prevents "valve closed during fire" disaster; (d) Fast operation for emergency: disc 90° rotation - manual ≤3 seconds (worm gear/handle), electric 1-5 seconds - quickly opens water supply during fire emergency (gains valuable firefighting time), quickly closes for zonal water cut-off during maintenance; (e) Compact + space-saving: butterfly valve body length only 1/3-1/2 of same-DN gate valve - much shorter, lighter; ideal for narrow spaces (ceilings, pipe shafts, underground garages, mechanical rooms) common in high-rise buildings; (f) Low flow resistance: straight-through flow, fully open disc parallel to flow - resistance far lower than gate/globe - minimizes pressure loss, ensures sufficient water pressure/flow at end sprinklers/hydrants (critical for fire suppression - low pressure = ineffective sprinklers); (g) Reliable soft sealing: EPDM (water/weathering, ≤120°C), NBR (oil/water), PTFE (chemical/corrosive), Viton (high-temp/oil) - elastic, aging-resistant, water-resistant; disc + seat close fit = bidirectional zero leakage (no water waste, maintains system pressure); (h) Durable materials: body ductile iron (GGG40, standard fire valve), cast steel (WCB, higher pressure), stainless SS304/316 (corrosive); disc ductile iron with plastic coating (corrosion-resistant, smooth, low torque) or stainless SS304/316; stem SUS410 (13Cr, general), SUS316 (corrosion), duplex stainless (high strength/corrosion); (i) Multiple connections: flange (rigid, high pressure, easy remove), wafer (compact/light, clamped between flanges), groove (grooved) (fast install with roll-groove pipe + clamp, common in fire sprinkler systems - Victaulic style); (j) Multiple drives: manual handle (small DN), worm gear (larger DN, labor-saving, self-locking), electric (remote/automated, fast), pneumatic (fast, hazardous), electro-hydraulic (high torque, large DN); (k) Modular signal component: signal switch/encoder is modular - can be disassembled/replaced without removing the entire valve (easy maintenance, low downtime); (l) Wide size/pressure: DN50-400 (2"-16"), PN10/16/25 (1.0/1.6/2.5MPa, 150LB, JIS 5K/10K) - covers fire system sizes; (m) Temp: -10~80°C (fire water range - prevents freezing, handles warm water); (n) Media: water (primary - fire water), oil, gas; (o) Standards: GB/T 5135.6-2018 (fire signal butterfly valve - mandatory for Chinese fire systems), API 609, BS 5155, DIN 3202, ISO 5752; (p) Test: strength 1.5×PN, seal 1.1×PN; (q) Applications: automatic sprinkler systems (zonal control valve, alarm valve group front control, end test device control), fire hydrant systems (main pipe, branch pipe, fire pump outlet), high-rise buildings/large venues (residential, commercial, malls, hotels, hospitals), industrial/commercial facilities (factories, warehouses, power plants, chemical plants), other fire systems (tunnels, airports, railway stations). This is the reliable fire-signal supervisory butterfly valve solution for modern fire protection water systems.

The signal feedback (supervisory switch), fast emergency operation, compact space-saving design, low flow resistance for fire water pressure, bidirectional zero-leak soft sealing, multiple connections/drives, and fire-code compliance make this valve a specialized fire-protection supervisory butterfly valve - distinct from general industrial butterfly valves - designed specifically for fire water supply systems where remote status monitoring, fast emergency response, code compliance, and reliable water delivery are critical. Compared to other butterfly valves: (a) vs Electric Flange Butterfly Valve (previous product): that one is general industrial electric butterfly - electric actuator, on-off/regulating 4-20mA, large-bore DN50-2000, soft/hard seal, -29~550°C, general industrial (water treatment/petrochemical/power/metallurgy); this one is fire-specialized signal butterfly - core = signal feedback/supervisory switch (not electric actuation primary), manual primary (worm gear/handle) + optional electric, DN50-400 smaller, soft seal only (EPDM/NBR/PTFE/Viton), -10~80°C fire water, GB/T 5135.6-2018 fire standard, fire red, flange/wafer/groove, for fire sprinkler/hydrant - fire-specific vs general industrial; (b) vs ordinary butterfly valve (no signal): ordinary butterfly has no signal feedback - requires manual site inspection (can miss closed valve, dangerous for fire); this one has supervisory switch - remote monitoring + alarm (code-required for fire systems in many regions); (c) vs fire signal gate valve: fire signal gate valve is gate-type (multi-turn, slow, bulky/heavy, long body); this one is butterfly - 90° fast, compact/short/light, better for narrow spaces, lower cost at larger DN - butterfly preferred for modern fire systems (especially high-rise/narrow); (d) vs wafer butterfly valve: this one offers flange/wafer/groove (groove = grooved coupling connection, very common in fire sprinkler - fast install); (e) vs general signal valve: this is butterfly-type signal valve (not gate/globe/ball) - compact/fast/low-cost. Signal feedback principle detailed: (a) travel switches (micro switches): mounted on gearbox/indicator, mechanically linked to valve stem via cam/gear; (b) when stem rotates (disc opens/closes), cam rotates and activates/deactivates micro switches at preset positions (fully open, fully closed, sometimes intermediate); (c) switches output dry contacts - NO (normally open) and NC (normally closed) - wired to fire alarm control panel (FACP) or building management system (BMS); (d) FACP monitors contact status - if valve open = NO closed (or NC open), if closed = opposite; (e) supervisory signal: in fire systems, valve status is a supervisory signal (not alarm) - indicates "valve not in normal open position" - FACP shows supervisory alarm (distinct from fire alarm); (f) optional encoder: potentiometer/encoder tracks stem angle 0-90° → outputs 4-20mA analog (4mA=closed, 20mA=open) - precise position, remote visual on SCADA; (g) alarm conditions: valve closed when should be open (supervisory alarm), valve not responding (fault), intermediate position (partial - may indicate tampering/maintenance); (h) code requirement: many fire codes (NFPA 13, GB 50084, EN 12845) require supervisory switches on control valves in sprinkler systems - to prevent accidental valve closure (a leading cause of sprinkler system failure). Why signal feedback is critical for fire: (a) #1 cause of sprinkler system failure = control valve accidentally closed (during maintenance, tampering, negligence) - when fire occurs, no water reaches sprinklers; (b) supervisory switch = remote monitoring - FACP immediately alerts if valve closed - prevents this failure; (c) code-mandated: NFPA 13 requires supervisory devices on all control valves; GB 50084 (Chinese sprinkler code) requires signal valves; (d) this valve = code-compliant signal butterfly valve. Fast operation for fire emergency: (a) fire requires immediate water - fast valve operation critical; (b) butterfly 90° = fast (manual ≤3s with worm gear, electric 1-5s); (c) gate valve multi-turn = slow (30-60s+ for large DN) - too slow for emergency; (d) butterfly preferred for fire systems. Compact for high-rise/narrow spaces: (a) high-rise buildings have limited space - pipe shafts, ceilings, mechanical rooms; (b) butterfly valve short body (1/3-1/2 gate length) + light = fits narrow spaces; (c) gate valve long/tall = doesn't fit; (d) butterfly dominant in modern high-rise fire systems. Low flow resistance for sprinkler pressure: (a) fire sprinklers require minimum pressure/flow at end of system (e.g., 0.05 MPa at remote sprinkler); (b) high resistance valves = pressure loss = insufficient sprinkler pressure = ineffective fire suppression; (c) butterfly valve low resistance (K~0.2-0.5) = minimal pressure loss = ensures end pressure; (d) gate valve also low resistance but bulky; (e) butterfly = low resistance + compact ideal. Grooved connection for fire sprinkler: (a) grooved (grooved coupling): pipe ends roll-grooved, valve has grooved ends, coupling (clamp) with gasket connects - very fast installation (no welding/threading), no fire risk during install, easy disassembly; (b) dominant in fire sprinkler systems (Victaulic style); (c) this valve offers grooved connection - ideal for sprinkler; (d) flange for high pressure/main pipe, wafer for compact, groove for sprinkler branch. Fire red coating: (a) fire valves are painted red (fire safety color code) - easy identification in emergency; (b) ductile iron body + epoxy red paint (corrosion-resistant, durable); (c) some regions require red for fire valves. Drive options for fire: (a) manual worm gear (most common for fire signal valves - reliable, no power needed, handwheel operation, self-locking); (b) manual handle (small DN ≤DN100); (c) electric (for remote/automated systems, fast, FACP-controlled); (d) pneumatic/electro-hydraulic (special/large DN); (e) manual primary because fire valves should be operable during power outage (fire may cut power). Test & certification: (a) strength test 1.5×PN (body); (b) seal test 1.1×PN (zero leakage); (c) signal function test - verify switch activation at open/close, contact resistance, signal output; (d) fire code certification - GB/T 5135.6, CCCF (China fire product certification) optional; (e) third-party (BV/SGS/TUV) optional. Important notes: (a) fire water only - not for other media unless specified; (b) -10~80°C - protect from freezing (insulate if <0°C); (c) install in accessible location - must be operable/inspectable (fire code requires accessible); (d) do not paint over signal device/nameplate; (e) signal wiring - use fire-rated cable, connect to FACP supervisory circuit; (f) periodic test - operate valve + verify signal (quarterly/annually per fire code); (g) grooved connection - use correct gasket, lubricate gasket, torque coupling bolts; (h) not for throttling - fully open or closed (fire valves are on-off, not regulation); (i) bidirectional - can install either direction (soft seal). The valve is manufactured under strict quality control with 100% body hydrostatic (1.5×PN), 100% seat leak (1.1×PN, zero), 100% signal function test (switches, 4-20mA if encoder), 100% pressure test, fire code compliance. With an 18-month warranty and OEM/ODM customization (material, size, pressure, connection, drive, signal type, encoder, coating, certification), this valve is a reliable, code-compliant, fire-signal supervisory butterfly valve for modern fire protection water systems.

1.Real-Time Signal Feedback + Supervisory Alarm

High-precision travel switches + linkage mechanism convert real-time fully-open/fully-closed/intermediate valve status to electrical signals (NO/NC dry contacts) transmitted to fire control room/FACP; optional encoder outputs 4-20mA analog for remote visual monitoring. If valve accidentally closed, blocked, or fails, signal change triggers supervisory alarm immediately - prevents "valve closed during fire" (a leading cause of sprinkler failure). Code-compliant supervisory switch per GB/T 5135.6-2018/NFPA 13.

2.Fast Operation for Fire Emergency

Disc rotates 90° for full open/close - manual operation ≤3 seconds (worm gear/handle), electric 1-5 seconds. Quickly opens fire water supply during emergency to gain valuable firefighting time; quickly closes for zonal water cut-off during system maintenance. Much faster than multi-turn gate valves (30-60s+) - critical for fire emergency response.

3.Compact Structure + Narrow-Space Installation

Body length only 1/3-1/2 of same-DN gate valve, lightweight, short face-to-face - ideal for installation in narrow spaces: ceilings, pipe shafts, underground garages, mechanical rooms of high-rise buildings/commercial centers. Greatly improves installation flexibility where space is limited. Wafer/groove options even more compact.

4.Low Flow Resistance + Reliable Water Delivery

Straight-through flow channel; fully open disc parallel to water flow minimizes obstruction. Flow resistance far lower than gate/globe valves - reduces pipeline pressure loss, ensures sufficient water pressure and flow at end sprinklers or fire hydrants (critical for effective fire suppression). Full-bore design for unobstructed water delivery.

5.Bidirectional Zero-Leak Soft Seal + Long Life

Seat: EPDM (water/weathering), NBR (oil/water), PTFE (chemical/corrosive), Viton (high-temp/oil) - excellent elasticity, aging resistance, water resistance. Disc and seat fit closely for bidirectional zero leakage. Ductile iron/cast steel/SS body, plastic-coated/SS disc, SUS410/316/duplex stem, anti-corrosion treatment - service life 8-12 years under normal fire water conditions.

6.Multiple Connections/Drives + Modular Signal + Fire Code

Connections: flange (rigid/high-pressure), wafer (compact/light), groove (grooved coupling - fast install, common in sprinkler systems). Drives: manual (handle/worm gear), electric, pneumatic, electro-hydraulic. Signal component modular - replace without removing entire valve. DN50-400 (2"-16"), PN10/16/25 (150LB/JIS 5K/10K), -10~80°C. Fire red coating. GB/T 5135.6-2018, API 609, BS 5155, DIN 3202, ISO 5752. 18-month warranty, OEM/ODM.

A Fire Signal Butterfly Valve operates on the principle of a quarter-turn rotating circular disc (butterfly plate) for on-off control of fire water, combined with a signal feedback (supervisory switch) mechanism that converts the disc's rotational position into electrical signals for remote monitoring and alarm - the disc is mounted on a rotating stem; when the disc is parallel to flow (0°), the valve is fully open (fire water flows with low resistance); when the disc is rotated 90° to be perpendicular to flow, the valve is fully closed (disc blocks flow, soft seat seals); a mechanical linkage (cam/gear) on the stem activates high-precision travel switches at preset positions (fully open, fully closed, intermediate), outputting NO/NC electrical signals to the fire alarm control panel (FACP) - if the valve is accidentally closed, blocked, or fails, the signal changes and triggers a supervisory alarm - with fast 90° operation, compact body, low flow resistance, soft seal zero leakage, flange/wafer/groove connection, and manual/electric/pneumatic/electro-hydraulic drive - a code-compliant fire-signal supervisory butterfly valve for fire protection water systems. The valve consists of a body (ductile iron/cast steel/stainless, flange/wafer/groove ends), a circular disc (ductile iron plastic-coated or stainless, on stem), a stem (SUS410/316/duplex, rotating), a soft seat (EPDM/NBR/PTFE/Viton, in body), packing (stem seal), a drive operator (manual handle/worm gear, electric, pneumatic, electro-hydraulic), and a signal feedback unit (travel switches + cam/linkage, optional encoder + 4-20mA). Quarter-turn on-off principle: (1) fully open (0°): disc plane parallel to flow direction - fire water flows through annular space around thin disc; low flow resistance (K~0.2-0.5); (2) fully closed (90°): disc plane perpendicular to flow - disc edge compresses soft seat (EPDM/NBR/PTFE/Viton), seat deforms = bidirectional zero leakage; (3) fire valves = on-off only (fully open or fully closed - NOT throttling, per fire code); (4) 90° rotation = fast (manual ≤3s, electric 1-5s); (5) operator (worm gear/handle/electric) drives stem. Signal feedback (supervisory switch) principle - core feature: (a) mechanical linkage: stem rotation is transferred via gear/cam to signal unit (mounted on gearbox/top); (b) travel switches (micro switches): at preset angular positions (e.g., 0°=fully open, 90°=fully closed), cam lobe activates/deactivates micro switch; (c) switch output: each switch has NO (normally open) and NC (normally closed) dry contacts - voltage-free (user supplies monitoring voltage); (d) wiring to FACP: switches wired to fire alarm control panel supervisory input circuit (or BMS/SCADA); (e) status indication: FACP reads contact state - e.g., valve open = NO contact closed (conductive), valve closed = NO contact open; (f) supervisory alarm: if valve is not in normal open position (closed, partially open, fault), FACP detects contact change → triggers supervisory alarm (distinct sound/indicator - "supervisory" not "fire alarm"); (g) optional encoder: potentiometer/encoder coupled to stem → outputs 4-20mA analog proportional to angle (4mA=0° closed, 20mA=90° open) → precise position on SCADA/BMS graphic display; (h) intermediate signal: some models have switch at intermediate (e.g., 15° from closed) to detect "valve not fully open" (tampering/maintenance); (i) modular: signal unit is separate module - can be replaced without removing valve body. Why supervisory signal is critical (fire safety): (a) #1 cause of automatic sprinkler system failure = control valve accidentally closed (during maintenance, by unauthorized person, negligence) - when fire occurs, water cannot reach sprinklers; (b) ordinary valve = no remote status - must be manually inspected (often missed, quarterly inspection may be too late); (c) supervisory switch = 24/7 remote monitoring - FACP immediately alerts if valve closed - prevents this failure; (d) code requirement: NFPA 13 (US sprinkler standard) requires supervisory devices on all control valves; GB 50084 (Chinese automatic sprinkler code) requires signal valves (信号蝶阀 / 信号闸阀); EN 12845 (European) similar; (e) this valve = code-compliant signal butterfly valve (GB/T 5135.6-2018). Fast operation principle: (a) butterfly = 90° quarter-turn - one quick motion; (b) manual worm gear: handwheel rotates worm → worm gear → stem → 90° in ≤3s (gear ratio optimized for speed + torque); (c) electric: motor + gearbox → 1-5s; (d) vs gate valve: multi-turn (stem rotates many times to lift gate) - 30-60s+ for large DN - too slow for fire emergency; (e) fast = critical for fire (immediate water) and maintenance (fast zonal shut-off). Compact principle: (a) butterfly disc is thin - body is short (disc diameter ≈ pipe ID, body length ~0.5-1× DN); (b) gate valve body length ~2-3× DN (gate chamber + bonnet + stem); (c) butterfly = 1/3-1/2 gate length + lighter; (d) fits narrow spaces (pipe shaft, ceiling, garage) common in high-rise; (e) wafer/groove even shorter. Low flow resistance principle: (a) fully open disc = thin plate parallel to flow - minimal obstruction; (b) K factor ~0.2-0.5 (very low); (c) globe valve K=3-10 (S-shaped path); (d) low resistance = low pressure loss = water pressure/flow preserved to end sprinklers/hydrants; (e) fire code requires minimum residual pressure at remote sprinkler (e.g., 0.05 MPa / 7 psi) - low-resistance valves help meet this. Soft seal zero-leakage principle: (a) EPDM/NBR/PTFE/Viton seat in body bore; (b) disc closes (90°), disc edge compresses soft seat - seat deforms conforms to disc = zero leakage (bubble-tight); (c) bidirectional: seals both flow directions (soft seat on both sides or symmetric); (d) EPDM: water, weathering, ozone, ≤120°C - fire water standard; (e) NBR: oil/water, ≤80°C; (f) PTFE: chemical/corrosive, ≤180°C; (g) Viton: high-temp/oil, ≤200°C; (h) fire water = EPDM most common. Multiple connections: (a) flange: body flanges bolted to pipeline - rigid, high pressure, easy remove, for main pipe/high pressure; (b) wafer: thin body clamped between pipeline flanges with long bolts - compact/light/cheap, for branch/medium; (c) groove (grooved coupling): body has grooved ends, pipe roll-grooved, coupling clamp + gasket connects - very fast installation (no welding/threading), no hot work, easy disconnect - dominant in fire sprinkler systems (Victaulic style); (d) select per pipeline design. Multiple drives: (a) manual handle: small DN ≤DN100, direct lever 90°, simple/no power; (b) manual worm gear: larger DN, worm gear reduces effort, self-locking, handwheel, most common for fire signal valves (reliable, operable during power outage); (c) electric: motor+gearbox, remote/FACP-controlled, fast 1-5s, for automated systems; (d) pneumatic: compressed air, fast, hazardous; (e) electro-hydraulic: high torque, large DN; (f) manual primary for fire (power may fail during fire - manual operability essential). Grooved connection detailed (fire sprinkler): (a) pipe end roll-grooved (cold-formed groove, no cutting); (b) valve end has matching groove; (c) coupling = split metal clamp + rubber gasket; (d) gasket sits over groove, clamp over gasket, bolts tightened → gasket compressed = seal; (e) advantages: fast install (minutes), no welding (no fire hazard during install), flexible (allows some deflection/vibration), easy disconnect (maintenance), pressure-rated (up to PN25); (f) standard in fire sprinkler worldwide (Victaulic, Gruvlok, Mech); (g) this valve offers grooved ends. Fire red coating: (a) fire safety color code: fire valves = red (Ral 3000 or similar) - immediate identification in emergency; (b) ductile iron body → blast clean → epoxy red paint (corrosion-resistant, durable, indoor/outdoor); (c) some regions require red for all fire protection valves; (d) nameplate/signal device not painted over. Testing: (1) body hydrostatic 1.5×PN - zero external leak; (2) seat leak 1.1×PN - zero leakage (soft seal, bubble test); (3) signal function test - verify switch activation at fully open/fully closed, contact resistance (<100mΩ), insulation resistance, 4-20mA output (if encoder); (4) operation test - full open/close, torque, timing; (5) pressure test per GB/T 5135.6/API 609; (6) appearance/coating - red paint thickness/adhesion; (7) marking - size/pressure/material/standard/signal. FACP integration: (a) switch wiring: NO/NC common (COM) - 3-wire per switch (COM, NO, NC) or 2-wire (NO+COM); (b) fire-rated cable: use fire-resistant cable (e.g., LSZH, PH30/PH60/PH120) per code; (c) FACP supervisory module: connect to supervisory input module (not alarm input) - FACP distinguishes supervisory vs fire alarm; (d) monitoring: FACP displays valve status (open/closed) on graphic/text; (e) alarm: if closed when should be open → supervisory alarm (buzzer + print + history); (f) BMS/SCADA: optional via 4-20mA encoder or Modbus. Maintenance (fire code): (a) quarterly: visually inspect valve position (should be open), signal indicator, no leaks; (b) annually: operate valve full open/close, verify signal to FACP, test supervisory alarm (close valve → FACP alarms), lubricate stem, inspect seat; (c) 5-year: replace seat/packing if needed, inspect signal switches; (d) record: all tests logged (fire marshal inspection); (e) never leave valve closed after maintenance without reopening + verifying signal. Important: (a) on-off only - do not use for throttling (partial opening = high velocity/cavitation/seat wear, and fire code requires fully open); (b) fire water - not for other media unless specified; (c) -10~80°C - insulate if ambient <0°C (freezing can damage seat/body); (d) accessible - fire code requires valve accessible for operation/inspection (not buried/blocked); (e) do not paint signal device, nameplate, stem; (f) signal wiring - fire-rated cable, correct polarity; (g) grooved coupling - use correct gasket, lubricate, torque per manufacturer; (h) periodic test mandatory per fire code. Operation: (1) open: rotate handwheel/handle counterclockwise (or electric open) → disc to 0° parallel → signal "open" to FACP; (2) close: rotate clockwise → disc to 90° perpendicular → seat seals → signal "closed" → FACP supervisory alarm (if not expected); (3) indication: local position indicator (open/close) on gearbox; (4) manual override (electric): declutch motor, use handwheel.

• Automatic Sprinkler System

Zonal control valves, control valves in front of alarm valve groups (wet/dry/pre-action), end-of-line test device control valves in automatic sprinkler systems. Signal feedback to FACP ensures valve is open (supervisory alarm if closed); fast operation for zonal maintenance without affecting other areas; low flow resistance ensures sprinkler water pressure; grooved connection for fast sprinkler pipe install. Code-compliant per GB 50084/NFPA 13.

• Fire Hydrant System

Main pipe, branch pipe, and fire pump outlet control valves for indoor/outdoor fire hydrant systems. Fast open ensures rapid water supply during fire fighting; signal monitoring verifies valve ready; compact for building pipe shafts; bidirectional zero leakage maintains system pressure. For high-rise, commercial, industrial hydrant networks.

• High-Rise Buildings + Large Venues

Fire protection systems in high-rise residential, commercial centers, shopping malls, hotels, hospitals, schools, stadiums - compact body fits narrow pipe shafts/ceilings/underground garages; signal feedback to building FACP/BMS for centralized monitoring; fire red coating for easy identification; multiple connection options for diverse piping. Essential for modern building fire safety.

• Industrial + Commercial Facilities

Factories, warehouses, power plants, chemical plants, logistics centers - fire water pipelines with corrosive/dusty conditions; ductile iron/cast steel/stainless body options; EPDM/NBR/PTFE seats; manual worm gear reliable without power; signal alarm for unattended areas; flange/wafer/groove for different pipe standards. Reliable for industrial fire protection.

• Public Infrastructure + Transportation 

Tunnels, airports, railway stations, subway stations, car parks, exhibition centers - large-space fire protection with long pipe runs; low flow resistance preserves end pressure; signal monitoring in central control room; fast emergency operation; compact for tunnel/ceiling installation. 18-month warranty, OEM/ODM customization (size/connection/drive/signal/certification).

Our Fire Signal Butterfly Valves are manufactured under an ISO 9001:2015 certified quality management system, with every valve undergoing rigorous inspection and testing at each production stage - because these fire-signal butterfly valves are life-safety fire protection components used in automatic sprinkler systems, fire hydrant systems, high-rise buildings, and public facilities where valve failure, seal leakage, signal malfunction, or accidental closure can prevent water delivery during a fire, causing property damage and loss of life - fire valves require strict code compliance, body integrity, zero seat leakage, and 100% signal function verification. Raw material control: every body/disc/stem material batch comes with material certificate (chemical + mechanical per heat); ductile iron (GGG40, tensile ≥400MPa), cast steel WCB, stainless SS304/316 verified by PMI; EPDM/NBR/PTFE/Viton seats verified for grade/hardness/aging; signal switches (micro switches, UL/TUV/CE certified components), encoder (if specified) verified; fire-rated cable glands.

Body manufacturing: (a) casting (ductile iron/cast steel/stainless) - sand casting; (b) heat treatment (ductile iron annealing, WCB normalizing/tempering, stainless solution annealing); (c) 100% visual; (d) NDT - radiographic/ultrasonic of critical sections (for large DN); (e) wall thickness (per GB/T 5135.6/API 609); (f) end machining (flange/wafer/groove - groove dimensions per grooved coupling standard); (g) seat recess machining; (h) stem bore/bearing; (i) chemical/mechanical/hardness per heat; (j) surface preparation (blast clean) + fire red epoxy coating (paint thickness 60-100μm, adhesion test, salt spray for outdoor); (k) nameplate (stainless, engraved - size/pressure/material/standard/year).

Disc manufacturing: (a) cast/forged disc; (b) plastic coating (nylon/epoxy, for ductile iron - corrosion-resistant, smooth, low torque) or stainless; (c) disc edge machining (sealing surface); (d) stem hole/keyway; (e) coating adhesion test; (f) dynamic balance.

Seat manufacturing: (a) EPDM/NBR rubber molded (hardness 60-75 Shore A, tensile, aging test, water absorption); (b) PTFE/Viton machined/molded; (c) dimensional check, hardness, compression set; (d) fire water compatibility (EPDM for water).

Stem: (a) SUS410/SUS316/duplex machined; (b) surface treatment (SUS410: hardened; stainless: passivated); (c) dimension check, straightness. Signal unit: (a) travel switches (micro switches) - electrical test (contact resistance, insulation, actuation force); (b) cam/gear machining (position accuracy); (c) encoder (if specified) - 4-20mA calibration; (d) housing (waterproof, IP65/IP67); (e) function test: switch activation at preset angles (0°/90°), signal output, wiring; (f) modular assembly (easy replace).

Assembly: (1) install seat (bonded/inserted); (2) install stem + bearings + packing; (3) install disc (align with stem, key/pin); (4) install operator (worm gear/handle/electric); (5) install signal unit on top - couple cam to stem, set switch positions (fully open/fully closed), wiring; (6) full stroke test (0-90°, smooth); (7) signal calibration: set NO/NC at fully open (0°) and fully closed (90°) - verify contact change; (8) encoder calibration (4mA=closed, 20mA=open); (9) local position indicator set.

Pressure testing: (1) 100% body hydrostatic shell 1.5×PN - zero external leak; (2) 100% seat leak 1.1×PN - zero leakage (soft seal, bubble test, bidirectional); (3) 100% air tightness (low-pressure air); (4) strength + seal per GB/T 5135.6-2018 / API 609. Signal function testing (100% - critical for fire valves): (1) switch activation: rotate valve from closed→open - verify "open" switch activates at 0° (±2°); rotate open→closed - verify "closed" switch at 90° (±2°); (2) contact output: measure NO/NC contact resistance (<100mΩ when closed, >100MΩ when open), insulation resistance (>500MΩ@500VDC); (3) alarm simulation: close valve → verify signal change (simulates FACP alarm); (4) encoder (if specified): 4-20mA output linearity, span/zero, accuracy ≤±1%; (5) wiring/cable gland: waterproof test; (6) signal label: wiring diagram on housing.

Function testing: open/close torque, 90° travel, disc position, end dimensions (flange/wafer/groove), face-to-face, seat sealing, operator function (manual/electric), signal function, coating thickness/adhesion, nameplate marking, fire red color, grooved end dimensions (if groove).

Fire code compliance: (a) GB/T 5135.6-2018 (fire signal butterfly valve) - design/test/marking; (b) GB 50084 (automatic sprinkler) - signal valve requirement; (c) CCCF (China fire product certification) optional; (d) NFPA 13 (US) supervisory switch; (e) third-party fire test (if required).

Coating & marking: exterior - fire red epoxy (Ral 3000 or customer red), interior - epoxy for water; valve permanently marked with DN, PN, material, standard (GB/T 5135.6), open/close direction, signal wiring, manufacturer, year; nameplate (stainless, corrosion-resistant); signal unit has wiring diagram label.

Documentation: shipped with hydrostatic test report, material certificate, seat leak report, signal function test report (switch calibration, 4-20mA if encoder), installation/operation/maintenance manual (including FACP wiring, signal wiring diagram, fire code requirements, periodic testing), fire code compliance certificate (if applicable), wiring diagram.

Warranty: 18 months from shipment or 12 months from installation (valve body); signal unit/electric actuator 12 months; extended warranty and third-party inspection (BV, SGS, TUV) and CCCF fire certification available.

Q: What is a fire signal butterfly valve, and why is signal feedback required for fire sprinkler systems?

A: A fire signal butterfly valve (also called supervisory butterfly valve or signal butterfly valve) is a butterfly valve equipped with a supervisory switch (signal feedback device) specifically designed for fire protection water systems (automatic sprinkler, fire hydrant). It combines: (a) butterfly valve on-off (disc rotates 90° to open/close fire water); (b) signal feedback - high-precision travel switches convert the valve's real-time open/close status into electrical signals (NO/NC dry contacts) sent to the fire alarm control panel (FACP) or building management system (BMS), so the fire control room can remotely monitor valve status without manual inspection; (c) supervisory alarm - if the valve is accidentally closed, blocked, or fails, the signal changes and triggers an alarm. Why signal feedback is required: (a) #1 cause of automatic sprinkler system failure = control valve accidentally closed (during maintenance, by unauthorized person, or negligence) - when a fire occurs, water cannot reach the sprinklers, so the system fails; (b) ordinary valve (no signal) requires manual on-site inspection (often quarterly) - a valve could be closed for months before being discovered, creating a major fire hazard; (c) supervisory switch provides 24/7 remote monitoring - FACP immediately alerts if valve is not in normal open position (supervisory alarm), preventing this failure; (d) code requirement: NFPA 13 (US automatic sprinkler standard) requires supervisory devices on all control valves in sprinkler systems; GB 50084 (Chinese automatic sprinkler code) requires signal valves (信号蝶阀 / 信号闸阀) on sprinkler piping; EN 12845 (European) has similar requirements; (e) insurance requirement: many insurers require supervised valves for premium discounts. How it works: (a) travel switches (micro switches) mechanically linked to valve stem; (b) when valve fully open → "open" switch activated → FACP shows "normal/open"; (c) when valve closed (even partially) → switch deactivates → FACP detects change → supervisory alarm (distinct from fire alarm - indicates "system impairment, not fire"); (d) optional encoder outputs 4-20mA for precise position/visual display. Butterfly vs gate for fire signal: (a) fire signal butterfly valve (this valve): 90° fast (≤3s manual), compact/short/light (fits narrow pipe shafts/ceilings), low cost, low flow resistance - dominant in modern high-rise fire systems; (b) fire signal gate valve: multi-turn slow (30-60s), bulky/long/heavy, higher cost - older style, less common now; (c) butterfly preferred for new installations. This valve is code-compliant (GB/T 5135.6-2018, API 609), with signal feedback, fast operation, compact design - ideal for modern fire protection. Note: (a) fire signal valves are normally open (fully open during normal operation - water ready); (b) only closed during maintenance/emergency; (c) signal monitors "is it open?" - if not, alarm.

Q: How does the signal feedback (supervisory switch) work, and how do I wire it to the fire alarm panel?

A: Signal feedback mechanism: (a) mechanical linkage: valve stem rotation is transferred via gear/cam to the signal unit (mounted on top of gearbox/operator); (b) travel switches (micro switches): at preset angular positions (typically 0° = fully open, 90° = fully closed), a cam lobe activates or deactivates a micro switch; (c) switch contacts: each micro switch has 3 terminals: COM (common), NO (normally open), NC (normally closed) - these are dry contacts (voltage-free, no internal power); (d) when switch activated (e.g., valve open), NO closes (conductive) and NC opens; when deactivated (valve closed), NO opens and NC closes; (e) optional encoder: potentiometer/encoder coupled to stem → outputs 4-20mA analog proportional to angle (4mA = 0° closed, 20mA = 90° open) for precise position. Wiring to FACP (Fire Alarm Control Panel): (1) identify switch type: usually 2 switches (open + closed) or 1 switch (open/close); each has COM/NO/NC; (2) use fire-rated cable: fire-resistant cable (e.g., LSZH low-smoke zero-halogen, PH30/PH60/PH120, or fire-rated shielded) per local fire code - cable must survive fire for specified time; (3) connect to FACP supervisory module: NOT fire alarm input - use supervisory input module (monitor module) - FACP distinguishes "supervisory" (valve impairment) from "fire alarm"; (4) wiring example (open supervision): (a) FACP supervisory module has 2 terminals (IN+, IN-); (b) connect FACP IN+ → valve switch COM; (c) connect valve switch NO (for "valve open = circuit closed") → FACP IN-; (d) when valve open → NO closed → FACP sees continuity = "normal"; (e) when valve closed → NO open → FACP sees open circuit → supervisory alarm; (5) or use NC (some prefer NC = fail-safe - wire break also alarms); (6) end-of-line resistor (EOL) - FACP supervisory circuits often require EOL resistor (e.g., 47kΩ) at last device to detect wire break; (7) multiple valves: each valve on separate supervisory input (or addressable module) - FACP identifies which valve; (8) encoder (4-20mA): connect to PLC/BMS analog input (4-20mA), power supply (24VDC) for 2-wire loop; (9) ground/shield: shielded cable - drain wire grounded at one end (FACP) to prevent noise. FACP programming: (a) configure input as supervisory (not alarm); (b) set device label (e.g., "Sprinkler Zone 3 Control Valve"); (c) set alarm type (supervisory - latching, requires reset); (d) test: close valve → FACP shows supervisory alarm with device label; (e) history/logging. Verification test: (a) after wiring, operate valve closed → verify FACP alarms (correct device, supervisory type); (b) open valve → verify FACP returns to normal; (c) test wire break (disconnect wire) → FACP should alarm (trouble/supervisory); (d) record test (fire marshal may inspect). Important: (a) consult FACP manufacturer for exact module/wiring (addressable vs conventional); (b) do not power switches directly - they are dry contacts (FACP provides monitoring voltage); (c) waterproof cable gland on valve signal housing (IP65/IP67); (d) label wires at both ends; (e) do not run signal cable parallel to power cable (interference) - separate conduit; (f) periodic test (quarterly/annual) - verify signal to FACP. This valve comes with wiring diagram label on signal unit and in manual - follow for exact terminal assignments.

Q: What connection type should I choose - flange, wafer, or groove (grooved)?

A: Flange connection: Valve body has integral flanges at both ends - bolted directly to pipeline flanges with gasket. Advantages: (a) rigid/strong - suitable for higher pressure (PN25), main pipes, large DN; (b) easy install/removal - unbolt flanges, valve removed without cutting pipe; (c) standard - matches common pipeline flanges (GB/DIN/ANSI/JIS); (d) can support pipe weight. Disadvantages: (a) heavier/costlier than wafer; (b) longer than wafer. Use for: main fire water pipes, high pressure (PN25), large DN (≥DN200), where valve removal for maintenance needed. Wafer connection: Thin body, no flanges - valve is clamped between two pipeline flanges using long bolts passing through valve body. Advantages: (a) very compact/light/cheap; (b) short face-to-face; (c) easy for small/medium DN. Disadvantages: (a) less rigid - not for high pressure/large DN; (b) requires long bolts (span both flanges + valve); (c) harder to install (align all long bolts); (d) cannot remove valve without disconnecting pipeline (bolts through both flanges). Use for: branch pipes, low/medium pressure (PN10/16), small/medium DN (≤DN150), cost-sensitive, compact spaces. Groove (grooved coupling) connection: Valve body has grooved ends (roll-groove profile); pipe ends are roll-grooved (cold-formed groove); a grooved coupling clamp (split metal clamp + rubber gasket) connects valve to pipe. Advantages: (a) very fast installation (minutes - no welding, no threading); (b) no hot work (no fire hazard during installation - important in buildings); (c) flexible - allows some angular deflection, vibration, expansion; (d) easy disconnect (loosen clamp, remove - for maintenance); (e) pressure-rated (up to PN25); (f) dominant in fire sprinkler systems worldwide (Victaulic, Gruvlok, Mech style). Disadvantages: (a) requires grooved pipe + couplings (additional parts); (b) slightly larger OD than flange; (c) not for very high pressure (>PN25). Use for: fire sprinkler branch lines (most common), commercial buildings, fast-track projects, where no welding allowed. Selection guide: (a) sprinkler branch pipes, fast install, no welding → groove (most popular for fire sprinkler); (b) main pipe, high pressure, large DN, removable → flange; (c) small branch, low pressure, cost-sensitive, compact → wafer; (d) match existing pipeline - if pipeline is grooved → groove valve; if flanged → flange; (e) DN ≤DN150 → wafer/groove; DN ≥DN200 → flange/groove; (f) PN25 → flange/groove (not wafer). This valve offers all three - specify when ordering. Note: (a) grooved connection requires correct gasket (EPDM for fire water, NBR for oil), lubricate gasket (silicone grease, not petroleum-based), torque coupling bolts per manufacturer (usually 25-40 Nm depending on size); (b) flange gasket - spiral wound or rubber (EPDM) for fire water; (c) wafer - use ring gaskets + long bolts (grade matching pressure); (d) grooved couplings are standardized (Victaulic Style 77/99, etc.) - verify compatibility.

Q: Manual vs electric drive for fire signal butterfly valve - which is standard for fire systems?

A: Manual worm gear (standard for fire signal valves): Handwheel + worm gearbox drives stem 90°. Advantages: (a) no power required - operable during power outage (fire often causes power loss - manual operability critical); (b) reliable/simple - no motor/electronics to fail; (c) self-locking (worm gear holds position); (d) labor-saving (gear reduces effort for large DN); (e) cost-effective. Disadvantages: (a) not remote-controlled (must go to valve); (b) slower than electric (but ≤3s still fast). Use for: most fire signal valves - building sprinkler/hydrant control valves (normally open, rarely operated, must work during power failure). Manual handle (small DN): Direct lever handle for DN ≤DN100 - simplest, fastest, no power. Electric actuator: Motor + gearbox, remote-controlled via FACP/PLC or switch. Advantages: (a) remote operation - open/close from control room (no site visit); (b) fast (1-5s); (c) automated - can interlock with fire alarm (e.g., auto-open on fire signal, auto-close for zonal); (d) position feedback built-in. Disadvantages: (a) requires power - during power outage, may not operate (unless battery backup/ups); (b) more complex/costly (motor, gearbox, controller); (c) must have manual override (handwheel/crank for power failure - required by fire code); (d) fire code may require manual operability. Use for: automated fire systems, large DN, remote locations, where remote operation needed (e.g., pre-action sprinkler, deluge, special hazard). Pneumatic/electro-hydraulic: For special/large DN, hazardous areas - less common for standard building fire. Which is standard for fire systems? Manual worm gear is the standard/most common for fire signal butterfly valves because: (a) fire code emphasizes reliability during power failure - manual always works; (b) fire control valves are normally open and rarely operated (only maintenance/emergency) - no need for frequent remote operation; (c) signal feedback (not remote operation) is the key requirement - manual valve + signal switch = FACP monitors status, which is what code requires; (d) lower cost, less maintenance. Electric is used when: (a) remote operation required (e.g., pre-action/deluge systems that auto-open on fire alarm); (b) valve in inaccessible location; (c) large DN where manual effort too high; (d) integrated with building automation. Important: (a) if electric, must have manual override (handwheel/crank) per fire code - for power failure; (b) UPS/battery backup for electric fire valves (if required); (c) signal switch works regardless of drive (manual or electric - signal monitors position); (d) this valve offers manual (handle/worm gear) standard, electric/pneumatic/electro-hydraulic optional - specify. Recommendation: for standard building sprinkler/hydrant control valves → manual worm gear + signal feedback (code-compliant, reliable, cost-effective); for automated/special systems → electric + manual override + signal.

Q: What maintenance and periodic testing are required for fire signal butterfly valves?

A: Fire signal butterfly valves are life-safety devices - regular maintenance and testing are required by fire code (NFPA 25, GB 50261, etc.) and essential for reliability. Periodic inspection/testing schedule: Monthly/Quarterly: (1) visual inspection: verify valve in fully open position (indicator, handwheel position); (2) signal status: check FACP shows "normal/open" (no supervisory alarm); (3) no leaks (body, flange/groove, stem); (4) accessible (not blocked, not painted over, nameplate/signal device legible); (5) no damage (handle, signal housing, wiring). Annually (minimum): (1) full operational test: operate valve full close → full open (verify smooth, no binding, ≤3s manual); (2) signal test: while closing, verify FACP supervisory alarm triggers (correct device label, supervisory type); while opening, verify FACP returns to normal; (3) seat leak test: after close, verify no leakage through valve (visual/listen); (4) stem lubrication: lubricate stem/bearing with anti-seize (especially if rarely operated); (5) fastener check: tighten flange/groove coupling bolts if needed; (6) wiring check: inspect signal cable (no damage, waterproof gland tight, labels); (7) coating: touch up paint chips (prevent corrosion); (8) record: log all tests (date, result, technician) - fire marshal/insurance may inspect records. Every 3-5 years: (1) seat inspection/replacement: if leakage, wear, cracking, permanent set - replace seat (EPDM/NBR/PTFE/Viton ages over time); (2) packing replacement: if stem leaks; (3) signal switch inspection: clean, verify contact, replace if worn; (4) disc inspection: check plastic coating (if ductile iron coated) - touch up chips; (5) groove gasket (if grooved) - replace if compressed/cracked. After maintenance/repair: (1) reopen valve fully (critical - do not leave closed); (2) verify signal "open" at FACP; (3) pressure test (if seat replaced - 1.1×PN); (4) update records. Common maintenance issues: (a) valve seized (not operated for years) - lubricate stem, exercise gently (do not force - may break stem); (b) seat leak - seat worn/deformed (replace), or disc not fully closed (calibrate stop); (c) signal false alarm - switch misadjusted (recalibrate at 0°/90°), wiring loose, FACP programming error; (d) no signal - wiring break, switch failed, FACP module fault; (e) groove leak - gasket failed, coupling loose (retorque/replace gasket); (f) corrosion - paint chip (touch up), harsh environment (consider stainless body). Fire code requirements: (a) NFPA 25 (US): control valves inspected quarterly (visual), tested annually (operate + signal); (b) GB 50261 (China): sprinkler system maintenance - valves inspected monthly, tested annually; (c) records retained 3-5 years (per jurisdiction); (d) tagging: valve should have identification tag (zone, system, last test date); (e) only qualified personnel perform testing. Important: (a) never leave valve closed after testing/maintenance - always reopen + verify FACP signal; (b) notify building occupants/FACP before testing (supervisory alarm may trigger - put system in test mode); (c) do not paint signal device, nameplate, stem, wiring; (d) spare parts: keep seat, packing, signal switch, gasket for critical valves; (e) replace valve if body corroded, stem damaged, repeated failure - typically 8-12 year life (may extend with maintenance). This valve is designed for easy maintenance - modular signal unit (replace without removing valve), accessible stem, standard seats. With proper periodic testing, it will provide reliable fire protection for 8-12+ years.

Q: Can this valve be used for media other than fire water, and what are the temperature/pressure limits?

A: Primary use = fire water - this valve is designed and certified for fire protection water systems (automatic sprinkler, fire hydrant) with water as the medium. Temperature range: -10°C ~ 80°C (standard): (a) lower limit -10°C: fire water systems are typically indoor/heated (above freezing); if ambient below 0°C, valve/pipe must be insulated/heat-traced (freezing water expands and can crack body/seat); (b) upper limit 80°C: EPDM seat rated ≤120°C, but fire water is typically ambient (<40°C); 80°C covers warm water/hot water systems; (c) for >80°C: use Viton seat (≤200°C) or PTFE (≤180°C) - specify; (d) for <-10°C: special low-temp seat/body (not standard). Pressure range: PN10/16/25 (1.0/1.6/2.5MPa, 150LB, JIS 5K/10K): (a) standard fire systems are PN10/16 (most common); (b) PN25 for high-rise/high-pressure; (c) not for >PN25 (use gate/ball for higher). Other media (optional, with correct seat/material): (a) water (primary - fire water, domestic water, cooling water) - EPDM seat; (b) oil (light oil, lubricating oil) - NBR (nitrile) seat (EPDM swells in oil - do not use EPDM for oil); (c) gas (air, natural gas, inert gas) - EPDM/NBR (verify pressure/temp); (d) chemical/corrosive (acids, alkalis, mild corrosive) - PTFE seat + stainless body (not ductile iron); (e) hot water/oil (up to 200°C) - Viton seat; (f) NOT for: steam (high temp >200°C, use hard-seal valve), strong solvents (check PTFE compatibility), abrasive slurry (wears seat fast), high pressure >PN25, cryogenic. Material options for other media: (a) ductile iron body (standard) - water, non-corrosive; (b) cast steel WCB - oil/gas, higher pressure; (c) stainless SS304/316 - corrosive, chemical, food; (d) disc: ductile iron plastic-coated (water, corrosion-resistant) or stainless (corrosive); (e) stem: SUS410 (general), SUS316 (corrosion), duplex (high strength/corrosion). If you need non-fire-water media: (a) specify medium + temp + pressure when ordering - we configure seat/body/material accordingly; (b) note: signal feedback still works regardless of medium; (c) fire red coating may not be appropriate for non-fire use (can change color); (d) fire certification (CCCF) only for fire water use. Important: (a) standard valve = EPDM seat + ductile iron body = fire water only - do not use for oil (EPDM swells) or corrosive (ductile iron rusts); (b) EPDM vs NBR: EPDM = water/weathering/ozone (NOT oil/hydrocarbon); NBR = oil/water (NOT ozone/weathering as good); (c) PTFE = chemical/corrosive (but higher torque, not zero leakage like soft rubber); (d) Viton = high-temp/oil (expensive); (e) verify compatibility - if unsure, consult chemical resistance chart or us; (f) for fire water (95% of applications), standard EPDM + ductile iron is correct and code-compliant. This valve is primarily a fire water signal valve - for other media, specify and we will customize seat/body/material to suit.

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