01Source & pumping
Intake isolation, pump protection and filtration.
Water treatment valve solutions
Water treatment valves. Built for every flow stage.
From source-water intake and treatment to storage, distribution and building services, Diefei supplies isolation, non-return, air-release, filtration and control valves for dependable water flow.
Municipal and industrial duty Low-resistance flow paths ISO 9001 production
Typical water flow pathValve critical points
02Treatment
Process isolation, flow control and chemical compatibility.
03Storage
Level control, pressure control and reverse-flow prevention.
04Distribution
Main-line isolation, air release and surge protection.
05Building & HVAC
Isolation, balancing and serviceability at the point of use.
1972Manufacturing since
ISO 9001Quality management system
NSF 61/372Drinking-water certification listed
20+Export countries and regions
Application scope
One valve package.
Four water-system environments.
Water systems combine different duties: isolation, pump protection, flow control, air release, filtration and service access. Diefei builds the valve package around the full water path rather than a single product type.
Municipal water supply and drainage
Valve packages for intake stations, treatment plants, pumping stations, water mains, storage facilities and drainage networks.
Industrial water treatment
Isolation, non-return, control and filtration products for process-water systems, circulating water, wastewater and plant utilities.
High-rise building supply and drainage
Reliable shutoff, pressure management and reverse-flow protection for risers, pump rooms, storage tanks and drainage lines.
HVAC and air-conditioning water
Valves for chilled water, condenser water, plant-room isolation, balancing, air release and maintenance isolation.
Design priorities
Built around the duty.
Selected for the whole system.
A valve that works on the bench must also work with the pump, pipe, control sequence and maintenance plan. These three priorities guide the water-treatment valve selection.
Protect the pump
Slow-closing and dual-plate check valves help limit reverse flow, reduce water hammer risk and protect pump discharge lines.
Keep the flow path clean
Strainers, filters and low-resistance valve designs help protect equipment and preserve available pressure across the system.
Plan for service
Isolation points, accessible operators and suitable connection details support commissioning, inspection and maintenance without unnecessary shutdowns.
System architecture
Every stage has a duty.
Every choice affects flow.
A water-treatment valve package follows the water from source to point of use. Each interface needs the right mix of isolation, reverse-flow protection, air release, filtration, pressure control and service access.
From source water to the point of use
A representative municipal, industrial and building water flow path.
Isolation Flow protection Control & service
Selection note Valve type, pressure class, body material, seat, connection and actuator must be confirmed against the medium, size, temperature, pressure, installation position and project specification.
Product portfolio
A complete waterworks valve set,
organized by function.
The Diefei portfolio covers the main isolation, non-return, air-release, filtration and flexible-connection functions required in water supply, treatment and building water systems.
Isolation / flow control
Soft-seated butterfly valves
Wafer and flanged designs for water lines, plant rooms, pump stations and distribution mains.
View butterfly valves ↗
High-demand service
Metal hard-sealed butterfly valves
Triple-eccentric sealing, hard-alloy overlay and bidirectional shutoff for demanding water service.
View metal-seated valves ↗
Flanged installation
Flanged butterfly valves
Stable flange connection for larger pipes, isolation stations and high-rise building risers.
View the product ↗
Full-bore isolation
Gate valves
Resilient-seated, underground, electric non-rising-stem and cast-steel flanged options.
View gate valves ↗
Pump and surge protection
Dual-plate check valves
Low-resistance non-return protection for pump discharge, mains and compact wafer installation.
View check valves ↗
Air and vacuum control
Air-release valves
Automatic venting at high points and pump outlets to protect flow, pressure and pipeline integrity.
View air-release valves ↗
Pipeline protection
Y-strainers and filters
Filtration points that protect pumps, valves, meters and heat-transfer equipment from debris.
View strainers ↗
Flexible connections
Rubber expansion joints
Absorb pipe movement, misalignment and vibration at pumps, headers and equipment connections.
View expansion joints ↗Build the valve schedule around the complete water path.
Isolation, reverse-flow protection, air release, filtration and flexible connections can be reviewed together against the pipe size, pressure class, operating duty and project standard.
Key product parameters
Documented ranges.
Confirmed for the project.
The values below summarize the supplied Diefei water-treatment reference material. Final pressure, temperature, size, material and actuator ratings must be confirmed for the selected model and project condition.
| Product family | Pressure range | Size range | Temperature and design note |
|---|---|---|---|
| Wafer worm-gear soft-seated butterfly valve | PN 1.0 / 1.6 MPa | DN50 to DN1000 and aboveConfiguration-dependent | Low-torque, compact isolation and flow-control option for water, treatment and building services; manual, worm-gear, electric or pneumatic operation can be reviewed. |
| Metal hard-sealed butterfly valve | PN 1.0 / 1.6 / 2.5 MPaUp to 6.4 MPa depending on design | DN150 to DN2000 | Up to 425°C; triple-eccentric seal, cobalt-based hard-alloy overlay and bidirectional sealing, with installation not restricted by medium flow direction. |
| Wafer double-plate check valve | PN 1.0 to 2.5 MPa | DN40 to DN800 | Water and oil service; listed up to 80°C, or up to 200°C depending on construction. Low-resistance closing helps limit reverse flow and damaging water hammer. |
| CARX compound air-release valve | PN 1.0 / 1.6 MPa | DN25 to DN200 | Water and oil service from 0°C to 100°C. Automatic air release and air intake at pump outlets or pipeline high points help prevent negative-pressure damage. |
Parameters are reproduced from the supplied water-treatment solution material and can vary by size, body material, trim, seat, connection, actuator and operating condition. Confirm the current selection manual and technical confirmation before order.
Standards framework
One valve schedule.
Multiple project standards.
Water-treatment projects often combine domestic design requirements, international dimensional standards and export inspection rules. The valve schedule should identify the governing standard for design, face-to-face dimensions, pressure testing and inspection.
Pressure testing
General valve pressure-test reference covering shell strength and sealing checks across the supplied product range.
Butterfly valve design
Reference for general flanged and wafer butterfly valves used in isolation and flow-control duties.
Iron flanged gate valves
Design and manufacturing reference for resilient-seated and related iron gate valves in water systems.
Iron swing check valves
Reference for iron swing-check designs, including rubber-disc and related non-return valve constructions.
Metal-sealed butterfly valves
Industry reference for metal-seated butterfly valves used where temperature, wear or shutoff demand is higher.
European face-to-face dimensions
Dimensional reference for European butterfly-valve projects and replacement planning.
American butterfly valves
Design and testing reference for butterfly valves intended for American-standard project requirements.
Export inspection and testing
Inspection and pressure-test reference commonly requested for exported valves and project documentation.
Standard selection note: The governing edition, product scope and acceptance criteria must be stated in the project specification. Confirm the applicable design, face-to-face, testing and documentation requirements with Diefei before approval.
Quality and production assurance
Reliability is built
from material to dispatch.
Water infrastructure demands repeatable manufacturing, documented testing and a traceable quality record. Diefei combines in-house production with standards-based pressure testing and export documentation.
Control across the full manufacturing chain.
Diefei's in-house capabilities cover research and development, casting, machining and assembly. Every valve can be checked through the production route before packing and shipment.
1972Manufacturing since
GB/T 13927Shell and sealing pressure tests
200,000Listed check-valve disc switching cycles
20+Export countries and regions
Certification and market-access documentation
ISO 9001Quality management system
TS2713660-2028Special equipment manufacturing license
TSX71002520201157National type-test certificate
TSX73201004420240244National type-test certificate
CE / PEDDirective 2014/68/EU
NSF/ANSI 61 & 372Drinking-water and lead-free requirements
Certificate scope, product coverage and validity can vary by model, size and configuration. Confirm the current certificate for the selected valve before project approval.
Research, casting, machining and assembly are controlled as one production chain, supporting consistent material and process follow-up.
Products are tested against the supplied GB/T 13927 reference, with API 598 inspection available for applicable export requirements.
Current certificates, type-test records and inspection documents can be checked against the selected model and project specification.
Water treatment valve FAQ
Questions before you
select the valve.
Use these answers as an early selection guide. Final valve type, pressure class, materials, actuator and certification scope should be confirmed against the actual water system and project specification.
Which valves are used in water treatment systems?
Diefei supplies soft-seated and metal-sealed butterfly valves, resilient-seated and cast-steel gate valves, slow-closing and rubber-disc check valves, hydraulic control valves, air-release valves, backflow preventers, filters and rubber expansion joints. The final mix depends on the process stage, pipe size, pressure class, medium and operating method.
Which valve types suit municipal pumping stations and water mains?
Typical selections include soft-seated butterfly valves for isolation, slow-closing or dual-plate check valves for pump discharge, metal-sealed butterfly valves for demanding service, air-release valves for high points, and strainers or expansion joints where required. Selection should follow the pump curve, surge analysis, burial or chamber arrangement, and the project standard.
How does Diefei help control water hammer and reverse flow?
Slow-closing check valves and hydraulic pump-control valves can be selected to reduce reverse flow and limit surge pressure. Air-release valves support pipeline venting and vacuum protection, while control valves help manage pressure and flow transitions. The final solution should be checked against the system surge study and operating sequence.
Which standards and pressure tests apply?
Diefei references GB/T 13927 for pressure testing, GB/T 12238 for flanged and wafer butterfly valves, GB/T 12232 for iron flanged gate valves, GB/T 13932 for iron swing check valves and JB/T 8527 for metal-sealed butterfly valves. Export projects can also reference EN 558 Series 20, API 609 and API 598 inspection and testing requirements.
Are NSF/ANSI and CE/PED certifications available?
The supplied material lists CE/PED 2014/68/EU and NSF/ANSI 61 and 372 certification, together with ISO 9001 and a TS special equipment manufacturing license. Certification scope can vary by product, size and configuration, so the current certificate for the selected valve should be confirmed before project approval.
Start a water-treatment valve review
Send us the service, size and standard.
Share the medium, flow, pressure, pipe size, installation position and project standard so our team can review the valve, material and actuator configuration.
