The H77X Butterfly Check Valve is a check valve that is opened and closed through a butterfly plate rotating, designed for rapid blocking of media countercurrent. It adopts a clamp type connection (Wafer Type), with a compact structure and light weight, and relies on the media’s own flow to drive the butterfly plate opening and closing. It is suitable for one-way flow control of low-viscosity fluids such as water, air, and oil. It is widely used in medium and low-pressure pipeline scenarios such as water supply and drainage, HVAC, and fire protection systems.
Model analysis
H: Represents Check Valve.
7: The connection method is Wafer.
7: The structure is Butterfly.
X: The sealing surface material is rubber (such as nitrile rubber NBR, ethylene propylene ternary rubber EPDM).
Core features
Lightweight and compact structure
The clip-on design does not require flange bolt holes, and is directly clamped between the pipe flanges, saving installation space, and is especially suitable for narrow or dense pipeline layouts.
Low flow resistance high efficiency opening and closing
The butterfly plate is disc-shaped, and it is automatically opened to the full diameter when the medium flows forward (the opening degree can reach 90°), and the flow resistance is extremely low; the butterfly plate is quickly closed when the pump is stopped or countercurrent (closing time ≤0.5 seconds) to prevent the impact of the water hammer.
Reliable sealing performance
The valve seat adopts an elastic rubber sealing ring, which is flexible to fit the edge of the butterfly plate, and the sealing level can reach zero leakage (Bubble Tight), which is suitable for a medium with a certain particle content.
Optional fluoroelastomer (FKM) or polytetrafluoroethylene (PTFE) sealing, making it more corrosion-resistant.
Long wear-resistant life
The valve body materials are mostly ductile iron (QT450) and stainless steel (304/316), and the butterfly plate is stainless steel or aluminum bronze, which is corrosion-resistant and erosion-resistant.
Applicable temperature range: -15℃~120℃ (rubber seal), special materials can reach 180℃.
Economical and practical
Compared with traditional lift check valves, the cost is reduced by about 30% to 50%, and the maintenance is simple, so you only need to check the wear of the seal ring regularly.
Technical parameters
Project Parameter Description
Nominal diameter DN50~DN1200 (common range)
Nominal pressure PN10~PN16 / Class150
Applicable temperature -15℃ ~ +120℃ (NBR rubber)
-20℃ ~ +180℃ (EPDM/fluororubber)
Valve body material Ductile iron, stainless steel (CF8/CF8M), cast steel
Sealing materials: Nitrile butadiene rubber (NBR), EPDM, fluoroelastomer (FKM)
Connection method: Wafer, optional flange (customized)
Installation direction Horizontal or vertical pipes (media flows from bottom to top)
Application areas
Municipal water supply and drainage: water pump outlet and sewage treatment plant prevent backflow.
HVAC: cooling water circulation system, fan coil pipeline.
Fire protection system: spray pump outlet, fire water tank in and out water pipe.
Industrial fluids: low-pressure steam, compressed air, and oil delivery pipelines.
Ship manufacturing: ballast water system, seawater desalination device.
Comparison with other check valves
Butterfly Check Valve (H77X):
Structural butterfly plate rotating, clamp-type installation
Extremely low flow resistance (at the same diameter as the pipe when fully opened)
Pressure bearing capacity medium and low pressure (≤PN16)
Fast closing speed (relying on spring assistance)
Lift check valve (H41H)
Structural valve disc lifts vertically, flange connection
Medium flow resistance (the valve disc partially blocks the flow channel)
Pressure bearing capacity medium and high pressure (up to PN40)
Slow shutdown speed (relying on media backflow speed)
Swivel check valve (H44H)
Structural valve disc rotating, flange or clamp connection
High flow resistance (the valve disc swing produces vortex current)
Pressure bearing capacity medium and high pressure (up to PN40)
Medium closing speed (valve flap gravity + media countercurrent)
Selection and installation suggestions
Key points for selection:
Media cleanliness: Use with caution if you contain solid particles or high viscosity fluids, which may hinder the butterfly plate or wear sealing ring.
Pressure matching: only for medium and low pressure systems (PN16 or below). It is recommended to choose a swivel or lift check valve for high pressure scenarios.
Vertical installation: It is necessary to ensure that the medium flows from bottom to top to avoid the butterfly plate being unable to close due to gravity.
Installation specifications:
Before installation, remove welding slag and iron filings in the pipeline to prevent scratches on the sealing surface.
The direction of the valve body arrow is consistent with the flow direction of the medium, and the clamp bolts must be tightened symmetrically and evenly.
Large diameter (DN≥300) valves need to be equipped with a support frame to avoid pipe vibration affecting sealing.
Maintenance and troubleshooting:
Frequently asked questions: seal ring aging, butterfly plate shaft stuck.
Maintenance cycle: Check the elasticity of the sealing ring every 1 to 2 years, and replace it if necessary; regularly fill the valve shaft with grease.
Emergency treatment: If the valve cannot be closed, the impurities between the butterfly plate and the valve seat can be removed and cleaned.
