REW Signature Product · CV Series
Check Valves
Swing · Lift · Wafer · Sandwich · 25mm – 1800mm
Automatic non-return valves preventing reverse flow and protecting pumps, compressors and pipeline systems. Engineered to BSS 5153 and API 6D standards with full-bore, low-resistance flow paths and reliable one-way flow control.
Size Range
25mm to 1800mm
Pressure Class
PN10 – PN40
Standards
BSS 5153 · API 6D
Body Material
CI · DI · CS · SS
ISO 9001:2015 Certified
BSS 5153 · API 6D · DIN 3202
100% Hydrostatically Tested
Since 1948 · Lahore, Pakistan
79+ Years of Valve Engineering
ISO 9001:2015 Certified
BSS 5153 · API 6D · DIN 3202
100% Hydrostatically Tested
Since 1948 · Lahore, Pakistan
79+ Years of Valve Engineering
CROSS-SECTION · 01
Product Overview
The Guardian of Flow Direction
A check valve is a self-actuated valve that automatically opens with forward flow and closes to prevent reverse flow. It requires no external power or manual intervention — making it the most reliable protection for pumps, compressors and pipeline systems.
REW manufactures check valves in four core configurations — Swing, Lift, Wafer and Sandwich types — per BSS 5153 and API 6D standards, from DN25 to DN1800, serving Pakistan's largest utilities, power plants and industrial facilities since 1948.
Automatic Operation
Self-actuating — opens with forward flow, closes on reverse. No power needed.
Equipment Protection
Prevents damaging reverse flow to pumps, compressors and turbines
Low Pressure Drop
Full-bore design with minimal flow restriction when open
Water Hammer Control
Non-slam and spring-assisted variants for surge protection
Product Variants
Four Core Configurations
Each engineered for specific flow protection challenges — from municipal water to high-pressure steam and oil transmission.
CV-SW
Type 01
Swing Check Valve
Traditional hinged disc design for horizontal and vertical upward flow. The disc swings open on
a hinge pin with forward flow and closes under gravity when flow stops. Full bore opening
minimizes pressure drop — ideal for water and low-viscosity fluids.
Full bore opening — minimal pressure drop
Horizontal & vertical upward installation
Stainless steel hinge pin for long service life
SS or Bronze seat rings — matched to media
Size: 50mm – 1800mm (2" – 72")
Pressure: PN10 – PN40 / Class 125 – 300
Material: CI, DI, CS, SS
Standard: BSS 5153, API 6D
Primary Applications
Water Supply
Pumping Stations
Irrigation
Fire Protection
CV-LF
Type 02
Lift Check Valve
Vertical disc movement guided by stem for precise sealing. The disc lifts vertically from the
seat with forward flow and drops back under gravity when flow ceases. Suitable for high-pressure
applications and vertical pipelines with superior sealing performance.
Vertical disc travel — precise, guided sealing
Superior sealing for high-pressure service
Piston or disc type available
Ideal for steam and high-temperature service
Size: 25mm – 600mm (1" – 24")
Pressure: PN16 – PN40 / Class 150 – 300
Material: CI, CS, SS
Standard: BSS 5153, API 6D
Primary Applications
High-Pressure Steam
Vertical Pipelines
Power Plants
Critical Service
CV-WF
Type 03
Wafer Check Valve
Compact wafer body fits between pipe flanges — no bolt holes required. Lightweight construction
with spring-assisted closure for non-slam operation. Space-saving design ideal for tight
installations and rapid cycling applications.
Spring-assisted closure — non-slam operation
Lightweight — up to 60% lighter than swing type
Compact footprint for tight installations
EPDM / PTFE / Metal seat options
Size: 50mm – 600mm (2" – 24")
Pressure: PN16 – PN40 / Class 150 – 300
Material: CI, DI, CS, SS
Standard: BSS 5153, API 6D
Primary Applications
Compact Layouts
Non-Slam Service
HVAC
Rapid Cycling
CV-SD
Type 04
Sandwich Check Valve
Dual-flange sandwich design bolted between pipe flanges with full perimeter sealing. Heavy-duty
construction for high-pressure and critical service. SS316 or Alloy 20 disc option available
for aggressive media.
Dual-flange construction — bolted, full seal
High-pressure rating for critical service
SS316 / Alloy 20 disc for corrosive media
Full perimeter gasket sealing
Size: 80mm – 1200mm (3" – 48")
Pressure: PN16 – PN40 / Class 150 – 300
Material: CI, DI, CS, SS
Standard: BSS 5153, API 6D
Primary Applications
High-Pressure
Oil & Gas
Chemical Plants
Critical Service
Manufacturing Process
Watch Our Production Line
From raw casting to final hydrostatic test — witness seven decades of valve engineering mastery in motion.
REW Check Valve Manufacturing
From casting to final testing — complete production process
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Applications
Serving 40+ Industries
REW check valves protect Pakistan's most critical pipeline infrastructure — from water utilities to oil refineries.
01
Water Supply
WASA, KWSB, municipal distribution, treatment plants
02
Wastewater
Sewage treatment, effluent handling, sludge lines
03
Hydropower
WAPDA projects, penstocks, turbine protection
04
HVAC
Chilled water, heating circuits, cooling towers
05
Fire Protection
Hydrant systems, sprinkler mains, fire water storage
06
Chemical
SS valves for corrosive media, acid, alkali service
07
Sugar Mills
Juice heaters, process lines, condensate return
08
Oil & Gas
Refineries, pipelines, OGDCL, PPL, PARCO terminals
09
Power Generation
Hydro, thermal — WAPDA, K-Electric, NEPRA
10
Mining
Slurry lines, dewatering, mineral processing
11
Food Processing
Sanitary lines, CIP systems, steam sterilization
12
Textile
Dyeing, steam distribution, process water
Working Principle
Automatic Flow Protection
Step-by-step operation sequence of a REW swing check valve — from forward flow to reverse closure.
01
Forward Flow — Disc Opens
As fluid flows in the forward direction, pressure differential pushes the disc open against gravity. The hinged disc swings away from the seat, allowing full-bore flow.
02
Full Open Position
Disc swings to maximum angle, creating an unobstructed flow path. Pressure drop is minimal — the valve acts almost like a straight pipe section.
03
Flow Decrease — Disc Returns
When flow velocity decreases or stops, the disc begins to swing back under gravity. Spring-assisted variants close faster for non-slam operation.
04
Reverse Flow — Disc Seals
Any reverse flow immediately pushes the disc against the seat. The disc seals tightly, preventing backflow and protecting upstream equipment.
05
Seat Contact — Zero Leakage
The disc contacts the seat ring with metal-to-metal or resilient seal. Zero visible leakage is achieved, protecting pumps from reverse rotation.
06
Continuous Cycle Protection
The valve continuously cycles open and closed with flow changes — no external power, no manual intervention. 79 years of REW engineering ensures reliable operation across millions of cycles.
CROSS-SECTION VIEW
Construction Details
Every Component Engineered
Detailed breakdown of each major component — function, material, and engineering importance.
Body
Primary pressure-containing component with flow passage. Cast in CI, DI, CS or SS. Houses the seat ring and hinge mechanism.
Bonnet / Cover
Covers the body opening and provides access for disc inspection and maintenance. Bolted or screwed design with gasket seal.
Disc / Flap
The closure element that swings or lifts to allow forward flow and closes to prevent reverse flow. SS, bronze or cast iron.
Hinge Pin
Stainless steel pin on which the disc swings. Precision-machined for smooth, friction-free operation over millions of cycles.
Seat Ring
Precision-machined sealing surface in the body. Stainless steel or bronze. Renewable design allows field replacement.
Spring (Wafer Type)
Stainless steel torsion spring assists disc closure for non-slam operation in wafer and sandwich check valves.
Gasket
Compressed asbestos-free, spiral wound or PTFE gasket between body and bonnet. Ensures pressure integrity at the joint.
Bolts & Nuts
B7/2H carbon steel or SS 304/316 bolts secure the bonnet to body. Torqued to specification for leak-free joint.
Technical Specifications
The Engineering Ledger
Complete specification sheet for REW Check Valves — every dimension, material, and standard documented for your engineering team.
Check Valve · Full Specification
DOC · CV-SPEC-2026
| Product Name | Check Valve — Swing, Lift, Wafer, Sandwich Types |
|---|---|
| Size Range | 25 mm (1") to 1800 mm (72") |
| Pressure Rating | PN10, PN16, PN25, PN40 · Class 125, 150, 300 |
| Body Material | Cast Iron (GG25), Ductile Iron (GGG40/50), Carbon Steel (WCB/WCC), Stainless Steel (CF8/CF8M) |
| Disc / Flap | Cast Iron, Ductile Iron, SS304, SS316, SS316L, Bronze, Alloy 20 |
| Hinge Pin | Stainless Steel 304, Stainless Steel 316 |
| Seat Ring | Stainless Steel, Bronze — matched to body material and service media |
| Bonnet Type | Bolted, Screwed — with gasket seal for pressure integrity |
| End Connection | Flanged (EN 1092-2, ANSI B16.5) / Wafer / Butt Weld |
| Operating Temp | -20°C to +425°C (depending on material) |
| Operation | Automatic (flow-actuated) / Spring-assisted (Wafer & Sandwich types) |
| Design Standards | BSS 5153, API 6D, DIN 3202, ISO 5153 |
| Face-to-Face | BSS 5153, API 6D, DIN 3202 |
| Flange Standard | BS 4504, ANSI B16.5, DIN 2501, EN 1092 |
| Testing Standard | API 598, ISO 5208 — Shell & Seat Hydrostatic Test |
| Coating / Paint | Epoxy Coated (250 microns DFT), Fusion Bonded Epoxy, Bitumen, Hot-Dip Galvanized |
| Applications | Water, Oil, Gas, Steam, Chemicals, Sewage, Irrigation, Fire Protection |
| Certification | ISO 9001:2015 · ISO 14001:2015 · ISO 45001:2018 · PSQCA |
| Origin | Manufactured in Lahore, Pakistan — Since 1948 |
Engineering Standards
Compliance & Certifications
Every REW check valve is manufactured and tested to internationally recognized standards.
BSS 5153
British Standard
Cast iron check valves for waterworks. Primary design standard for REW swing and lift check valves in municipal and industrial service.
API 6D
Pipeline Valves
Specification for pipeline valves. Covers design, manufacture, testing and documentation for check valves in oil and gas pipeline service.
DIN 3202
German Standard
Face-to-face dimensions for check valves. Ensures dimensional interchangeability with European manufacturers.
ISO 5208
International Standard
Industrial valves — Pressure testing of metallic valves. Harmonized international testing protocol for shell and seat tests.
API 598
Valve Testing
Standard testing procedures for all valve types. Shell test at 1.5×, seat test at 1.1× working pressure.
BS 4504
Flange Standard
Circular flanges for pipes, valves and fittings. PN designated. Covers bolt patterns and dimensions.
ANSI B16.5
American Flange Standard
Pipe flanges and flanged fittings. Class 125, 150, 300 ratings for American market compliance.
EN 1092
European Flange Standard
Flanges and their joints. Circular flanges for pipes, valves, fittings and accessories, PN designated.
ISO 9001:2015
Quality Management
Quality management system certified by TÜV Austria. Every valve traceable from raw material to final test.
Pressure Ratings
Working & Test Pressures
Pressure-temperature ratings for REW check valves across all standard pressure classes.
| Pressure Class | Working Pressure (bar) | Shell Test (bar) | Seat Test (bar) | Temperature Limit |
|---|---|---|---|---|
| PN10 | 10 | 15 | 11 | -20°C to +120°C |
| PN16 | 16 | 24 | 17.6 | -20°C to +200°C |
| PN25 | 25 | 37.5 | 27.5 | -20°C to +300°C |
| PN40 | 40 | 60 | 44 | -20°C to +425°C |
| Class 125 | 14.5 | 21.8 | 16 | -20°C to +200°C |
| Class 150 | 19.6 | 29.4 | 21.6 | -29°C to +425°C |
| Class 300 | 50 | 75 | 55 | -29°C to +425°C |
Dimensional Information
Size & Weight Data
Select a size to view detailed dimensional data for swing check valves. All dimensions in millimeters.
DN50
DN100
DN150
DN200
DN300
DN400
DN600
Nominal Size (DN)50 mm
Face-to-Face (L)203 mm
Height (H)165 mm
Flange Diameter165 mm
Bolt Circle125 mm
No. of Bolts4
Bolt DiameterØ19 mm
Weight (approx.)12 kg
The Forge
Forged with 79 Years of Mastery
From raw casting to final hydrostatic test — every REW check valve passes through a rigorous manufacturing process refined over seven decades at our Lahore facility.
01
Pattern & Casting
Precision wooden/metal patterns, green-sand and shell-mould casting in CI, DI, CS, SS
02
CNC Machining
CNC lathes and VMCs for seat, bore, flange and hinge pin machining to ±0.02mm tolerance
03
Disc & Seat Lapping
Precision lapping of disc-to-seat interface for bubble-tight shut-off. Seat ring press-fit or welded
04
Hinge Pin Assembly
Stainless steel hinge pin installed with precision bush. Disc swing tested for smooth, free movement
05
Hydrostatic Testing
Shell test at 1.5×, seat test at 1.1× working pressure — per API 598 / BSS 5153
06
Painting & Dispatch
Epoxy coating (250 microns DFT), marking, documentation pack with MTC and test certificate
FACILITY · LHR
CNC Machining · Lahore Plant
Quality Assurance
Zero-Defect Philosophy
Every valve undergoes rigorous inspection and testing before dispatch. Our quality system is certified to ISO 9001:2015 by TÜV Austria.
Incoming Inspection
Raw material verification — chemical composition and mechanical properties per EN 10204 3.1
Dimensional Inspection
CMM and precision instruments verify all critical dimensions against approved drawings
Hydrostatic Shell Test
1.5× working pressure held for specified duration. No visible leakage permitted
Seat Leakage Test
1.1× working pressure on seat. Zero visible leakage per API 598 / ISO 5208
Disc Swing Test
Disc swing freedom verified — smooth, unobstructed movement through full arc
Coating Inspection
DFT measurement, adhesion test, holiday detection for epoxy coatings
Identification Marking
Size, pressure class, material grade, heat number, manufacturer logo — permanently marked
Documentation
MTC, test certificates, dimensional reports, painting certificates — complete traceability
QA LAB · LHR
Technical Resources
Download Documentation
Complete technical documentation for engineering, procurement, and installation teams.
Technical Datasheet
Complete specifications, materials, dimensions, and performance data for all check valve variants.
Download →
Product Catalogue
Full REW product range with technical data, applications, and ordering information.
Download →
Installation Manual
Step-by-step installation guide, orientation requirements, and commissioning procedures.
Download →
Maintenance Manual
Preventive maintenance schedules, disc inspection, seat replacement, and overhaul procedures.
Download →
CAD Drawings
2D and 3D CAD files in DWG, STEP, and IGES formats for integration into your designs.
Download →
Certificates
ISO 9001, ISO 14001, ISO 45001, PSQCA, and type approval certificates.
Download →
Test Reports
Sample hydrostatic test reports, material test certificates, and inspection records.
Download →
Selection Guide
Technical guide for selecting the right check valve type and size for your application.
Download →
Installed Projects
Trusted Across Pakistan
REW check valves installed in critical infrastructure projects nationwide.
Water Supply
Lahore Water Treatment Plant
Lahore, Punjab
280+
Valves Installed
DN50-600
Size Range
2024
Completion
Oil & Gas
PARCO Oil Terminal Expansion
Mahmood Kot, Punjab
160+
Valves Supplied
PN25
Pressure Class
2025
Phase 2
Power Generation
Muzaffargarh Power Station
Muzaffargarh, Punjab
140+
Check Valves
PN40
Pressure Class
2025
Completed
Sugar Mills
Chashma Sugar Mill Expansion
Mianwali, Punjab
220+
Valves Installed
DN50-400
Size Range
2026
Ongoing
Technical FAQ
Engineering Questions
Answers to the most common technical questions about REW check valves.
What is the difference between swing and lift check valves?+
Swing check valves use a hinged disc that swings open with forward flow and closes under gravity. They offer full-bore opening with minimal pressure drop and are ideal for horizontal and vertical upward flow. Lift check valves use a vertically-guided disc that lifts from the seat. They provide superior sealing for high-pressure applications and are preferred for vertical pipelines and steam service.
What are the four types of check valves REW manufactures?+
REW manufactures four core configurations: (1) Swing Type — hinged disc for full-bore flow, (2) Lift Type — vertically-guided disc for high-pressure sealing, (3) Wafer Type — compact spring-assisted design for non-slam operation, and (4) Sandwich Type — dual-flange bolted design for high-pressure critical service.
What is the size range for REW check valves?+
REW manufactures check valves from DN25 to DN1800 (1" to 72"). Cast iron body check valves are available from 50mm to 1500mm. Cast steel body check valves (high pressure) from 50mm to 600mm. Stainless steel body check valves from 50mm to 300mm.
What pressure ratings are available?+
REW check valves are available in PN10, PN16, PN25, PN40 and Class 125, 150, 300. Shell test is performed at 1.5× working pressure and seat test at 1.1× working pressure per API 598 and BSS 5153 standards.
What standards do REW check valves comply with?+
REW check valves are manufactured to BSS 5153 and API 6D standards. Face-to-face dimensions follow BSS 5153, API 6D and DIN 3202. Flanges conform to BS 4504, ANSI B16.5, DIN 2501 and EN 1092. Testing is per API 598 and ISO 5208.
What body materials are available?+
Standard body materials include Cast Iron (GG25), Ductile Iron (GGG40/50), Carbon Steel (WCB/WCC), and Stainless Steel (CF8/CF8M). Hinge pins are always stainless steel. Seat rings are available in stainless steel or bronze, matched to the service media.
Can check valves be installed vertically?+
Yes, swing check valves can be installed in vertical pipelines with upward flow — the disc swings open with flow and closes under gravity. Lift check valves are specifically designed for vertical installation. For vertical downward flow, spring-assisted wafer or sandwich types are recommended.
What causes water hammer and how do check valves prevent it?+
Water hammer occurs when a pump stops suddenly and reverse flow slams the disc shut, creating a pressure surge. REW wafer and sandwich check valves feature spring-assisted closure that closes the disc before reverse flow fully develops, preventing destructive water hammer. Non-slam design is critical for pump protection.
How often should check valves be maintained?+
Recommended maintenance interval is 12-24 months depending on service conditions. Maintenance includes: disc swing inspection, seat ring condition check, hinge pin lubrication, gasket inspection, and bolt torque verification. Harsh environments (sewage, chemicals) may require more frequent maintenance.
What is the pressure testing procedure for REW check valves?+
Every valve undergoes: (1) Shell test at 1.5× working pressure for specified duration — no visible leakage permitted. (2) Seat test at 1.1× working pressure — zero visible leakage per API 598. Both tests are documented with test certificates provided with every shipment.
Can REW manufacture custom-sized check valves?+
Yes. REW can manufacture check valves in custom sizes from DN25 to DN1800, custom pressure classes, special materials, and non-standard face-to-face dimensions. Custom drawings are typically delivered within 48 hours of specification confirmation.
What is the typical lead time for check valve orders?+
Standard sizes (DN50-DN300): 2-4 weeks. Large sizes (DN350-DN600): 4-6 weeks. Special sizes (DN600+) or exotic materials: 6-10 weeks. Emergency orders can be expedited. Exact lead times confirmed at time of quotation based on current production schedule.
What seat materials are available?+
REW offers stainless steel seat rings for general and high-temperature service, and bronze seat rings for water and low-temperature applications. For wafer and sandwich types, EPDM, PTFE and Viton resilient seats are available for bubble-tight shut-off. Seat material is matched to the service media.
What is the difference between wafer and sandwich check valves?+
Wafer check valves fit between pipe flanges without bolt holes — lighter and more compact. Sandwich check valves have dual flanges that bolt between pipe flanges with full perimeter sealing — heavier duty and preferred for high-pressure service. Both use spring-assisted closure for non-slam operation.
What coating options are available?+
Standard coating is fusion-bonded epoxy (FBE) in blue or green, 250 microns DFT. Options include: bitumen coating for underground service, hot-dip galvanizing, bare finish, and custom RAL colors. Special coatings available for corrosive environments. Coating specification confirmed at time of order.
What documentation is provided with each shipment?+
Standard documentation includes: Material Test Certificate (MTC) per EN 10204 3.1, Hydrostatic Test Report (shell and seat), Dimensional Inspection Report, Painting/Coating Certificate, Certificate of Compliance, and Installation/Maintenance Manual. Third-party inspection certificates available on request.
What is the warranty period for REW check valves?+
Standard warranty is 12 months from date of commissioning or 18 months from date of shipment, whichever occurs first. Warranty covers manufacturing defects in materials and workmanship. Extended warranty available on request for critical applications.
Are spare parts available for REW check valves?+
Yes. Complete spare parts inventory maintained for all standard sizes. Available spares include: discs/flaps, seat rings, hinge pins, gaskets, bolts/nuts, and springs (for wafer/sandwich types). Spare parts typically dispatched within 48-72 hours.
How do I select the correct check valve type?+
Selection depends on: (1) Flow direction and pipe orientation — swing for horizontal, lift for vertical, (2) Pressure class — lift/sandwich for high pressure, (3) Space constraints — wafer for compact layouts, (4) Water hammer risk — spring-assisted wafer/sandwich for pump protection. Our technical team provides free selection guidance.
How do I request a quotation for check valves?+
Submit your requirements via the quote form on this page, email rewpak@yahoo.com, or call +92 322 276 2222. Include: size, pressure class, material, type (swing/lift/wafer/sandwich), seat material, end connection, quantity, and application details. Technical team responds within 24 hours with specifications, lead time, and pricing.
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Complete Your Pipeline Solution
Explore the full REW product range — engineered to work together as a complete flow control system.
ISO 9001:2015
Quality Management · TÜV Austria
ISO 14001:2015
Environmental Management
ISO 45001:2018
Health & Safety Management
PSQCA Mark
Pakistan Standards Certified
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