Backflow prevention
Compare KEHUA check valves from a China manufacturer. Review swing, lift, dual plate and other non-return series, flow duty and project quotation requirements.
API 594 / API 6D
Shortlist non-return valves from the system flow cases and approved mounting orientation, not pipe size alone. Compare swing, lift, piston and plate mechanisms separately from wafer installation. Follow the six catalogue series for section-drawing and RFQ checks; the product name does not by itself establish closing response or non-slam performance.
SERIES SELECTION COMPARISON
Start with fluid properties, flow range, approved installation orientation and available reversal or pump-trip cases, not pipe size alone. Compare the check valve's closing mechanism and guidance separately from its body connection. Confirm the offered section drawing, opening clearance and response limitations; a spring or product name alone does not guarantee non-slam performance.
Compare the swing valve's hinged disc travel with the guided member shown in the lift or piston section drawing. Confirm any spring, opening requirements, approved orientation and inspection access for the actual model. Keep the catalogue identity: a piston check valve must not be treated as an axial or nozzle design without evidence.
No. Dual plate identifies a closing mechanism, wafer describes mounting, and the butterfly-check catalogue entry needs its own section drawing. Review plates, hinges and any closing assistance independently of flange fit, then check pipe bore, opening clearance and approved orientation. Specify the offered mechanism and connection together instead of inferring one from the other.
Provide minimum, normal and maximum flow, fluid properties and available shutdown, reversal and surge cases. Request configuration-specific closing-response evidence and the limits of that assessment for each candidate check valve. Spring assistance or a series name is not a non-slam guarantee; agree seat-test acceptance separately from the system's dynamic response.
Use these decisions to compare existing catalogue constructions, not to assume interchangeability. Confirm medium suitability, size, pressure, temperature, materials and connections on the offered model’s datasheet and drawing.
TECHNICAL SELECTION
Use the sample catalogue figures as a starting point, not a universal rating. Confirm the exact model, size, pressure class, material, end connection and operating conditions on an approved datasheet before ordering.
Describe fluid density/phase, solids and cleanliness along with minimum/normal/maximum flow. Identify the intended backflow-protection duty for system review.
Provide DN/NPS, pipe bore, face-to-face and disc/plate opening clearance, installation orientation and access for inspecting the offered mechanism.
Give normal/design pressure and temperature plus available reverse-flow, pump-trip or surge cases. Nominal pressure class alone does not establish dynamic closing response.
Specify mating flange facing/drilling, wafer fit or other offered ends and nearby fitting clearances. Confirm mechanism and mounting approval on the same model drawing.
The figures describe the named catalogue construction. Size, pressure, temperature, material and end options are not interchangeable combinations; the maximum values do not apply simultaneously. Confirm the offered configuration, seat/seal compatibility, pressure–temperature limits and dimensions on its approved datasheet and drawing. The listed ranges summarize catalogue sizes, not every intermediate DN.
| Pressure class | Nominal sizes shown | End styles shown | Printed pages |
|---|---|---|---|
| ASME Class 150 | NPS 2–36 / DN 50–900 | RF / RTJ flange · BW | 40 |
| ASME Class 300 | NPS 2–36 / DN 50–900 | RF / RTJ flange · BW | 41 |
| ASME Class 600 | NPS 2–30 / DN 50–750 | RF / RTJ flange · BW | 42 |
RF = raised-face flange · RTJ = ring-joint flange · BW = butt-weld end
Source: supplied valve sample booklet; page numbers refer to its printed pages. Confirm the current model datasheet before ordering.
These are model- and class-specific examples. Not every size or end style is available in every configuration; final dimensions and ratings require an approved drawing and datasheet.
MANUFACTURER & CHECK VALVE SELECTION
KEHUA VALVE is Wenzhou Kehua Valve Co., Ltd., an industrial valve manufacturer based in Wenzhou, Zhejiang, China. This catalogue helps project buyers compare check valve series for backflow prevention. Select the disc mechanism and end connection separately, then verify the offered model against the piping and pump operating conditions.
Review the company and manufacturing informationReview the hinged-disc arrangement, required installation orientation, flow direction and space for inspection. Request the offered model's drawing and closing characteristics for the actual operating duty.
Confirm the guided-disc arrangement and permitted mounting orientation from the model drawing. Include minimum and normal flow conditions, pressure loss requirements and the proposed seat materials in the RFQ.
Dual-plate describes the closure arrangement; wafer describes a body installed between mating flanges. Check these features independently, including flange compatibility, internal clearance and the assembly drawing.
For piston or other catalogue series, request a section drawing identifying the actual closure mechanism. Do not treat piston and nozzle-style terminology as interchangeable without model evidence.
Review quality and qualification informationBackflow prevention
Use the check valve page to match the disc movement and closing response to pump, pipeline or process conditions.
A swing check valve opens through a hinged disc motion and closes to restrict reverse flow. The disc travel, pipe orientation and system flow history affect the review; pipe size alone does not determine closing behavior.
Swing check
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A lift check valve guides the closure member away from and back onto its seat. Guide and spring arrangements determine the offered installation requirements; do not infer mounting approval from a different lift-check model.
Lift check
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A dual-plate check valve uses two pivoting closure plates. The plate mechanism and body connection are separate choices. Review plate travel, spring details and the pipe bore before approving the offered assembly.
Dual plate
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Wafer identifies a check-valve body fitted between pipe flanges, not its internal closing mechanism. Identify the actual disc design on a section drawing and check opening clearance against the adjoining pipe and fittings.
Wafer
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The KEHUA catalogue uses piston check for this series. Request the piston, guide and any spring arrangement before evaluating opening response, pressure loss and orientation; the name does not establish an axial or nozzle design.
Piston check
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Butterfly check is the catalogue name for this non-return series, not a manually operated butterfly isolation valve. Confirm the closure plates, hinges and any closing assistance before assessing installation and reverse-flow response.
Butterfly check
Request this seriesTechnical data
Send a check valve schedule with mechanism, connection, permitted orientation and required materials identified per line. Attach flow/pump-duty information and pipe drawings; include quantity, destination, requested date and agreed material/inspection records. Require any missing reversal data, response assumptions and technical deviations to be stated in the offer. Use the line-item RFQ checklist and quality-document review to define the requested submission package. Unknown values can remain open for technical confirmation.
BUYER GUIDES
Use these guides to compare valve types, body materials and RFQ requirements before requesting a project quotation.
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