Stainless Steel Lift Check Valves

Stainless Steel Lift Check Valves (H41H Series) are automatic lift-type check valves professionally designed in accordance with GB/T 12235. The main body is made of 304/316/316L stainless steel, with a metal hard-seal structure where both the disc and seat are overlaid with tungsten carbide. They are specially designed to prevent backflow and protect pipelines and equipment.

The valve opens and closes automatically using medium pressure:

● Forward flow lifts the disc, allowing smooth passage.

● Backflow pushes the disc closed quickly by gravity and reverse pressure, forming a tight seal with zero leakage.

With a straight-through flow passage and vertical guide mechanism, the valve features stable action, fast response, and low flow resistance. It is suitable for long-term operation in harsh conditions such as corrosion, high temperature, and particle-containing media.

These valves are widely used in petrochemical, municipal water supply & drainage, power, food & pharmaceutical, metallurgy and other industries, especially for low-to-high pressure pipelines with corrosive media.

Core Technical Parameters

Structure & Material Composition

The entire Stainless Steel Lift Check Valves series features a corrosion-resistant stainless steel body and reinforced key sealing surfaces, significantly improving overall lifespan and reliability.

1. Main Components & Materials

● Body / Bonnet: 304, 316, 316L stainless steel (GB/T 1220)

● Disc: Stainless steel body + Stellite hard facing

● Seat: Stainless steel base + Stellite hard facing

● Guide: Forged stainless steel, smooth lifting without jamming

● Gasket: 316L spiral wound gasket (GB/T 4622.1)

● Bolts / Nuts: 304/316 stainless steel for corrosion matching

2. Structural Features

● Vertical lift guide, stable disc movement without deflection

● Straight-through flow path, low pressure loss

● Metal hard seal: high temperature, erosion & wear resistant

● Flange connection for easy installation & maintenance

● Fully automatic operation, no electric/pneumatic actuation needed

Design & Manufacturing Standards

Stainless Steel Lift Check Valves adhere to national standards throughout the entire process from design and manufacturing to inspection, ensuring interchangeability and safety.

● Valve Structure: GB/T 12235 (Lift Check Valve)

● Pressure & Temperature Rating: GB/T 12224

● Face-to-Face: GB/T 12221

● Flange: GB/T 9113 (RF)

● Material: GB/T 1220, GB/T 13401

● Hardfacing: GB/T 17491

● Pressure & Seal Test: GB/T 13927

● NDT: JB/T 6439

● Installation: GB 50235

Core Advantages

Strong corrosion resistance

Full stainless steel body for long service in chlorinated water, weak acid/alkali, seawater, and chemical media.

Reliable sealing & long service life

Disc and seat overlaid with Stellite alloy, wear and high-temperature resistant, greatly reducing leakage and replacement frequency.

Sensitive action & excellent anti-backflow

Vertical lift structure closes rapidly, effectively protecting pumps, compressors, heat exchangers from water hammer and backflow damage.

Low flow resistance & energy saving

Straight-through design ensures smooth flow, ideal for continuous industrial pipelines.

GB standard & interchangeable

Dimensions, flanges and pressure ratings comply with national standards, direct replacement for same-spec valves.

Selection Guide

1. Select by Pressure & Model

● PN16: Normal pressure water supply, circulating water

● PN25: General industrial oil, chemical media

● PN40/63: Medium-high pressure, high temperature, heavy impact

Suffix meaning:

● P: 304 stainless steel

● R: 316 stainless steel

2. Select by Corrosion

● Clean water, air, weak corrosion → 304 (P)

● Chloride, weak acid/alkali → 316 (R)

● Strong corrosion, high salt, high temp → 316L

3. Select by Temperature

● Normal temperature: All stainless steels

● High temp ≤550°C: Stellite hard seal

● Low temp ≥-40°C: Low-temperature stainless steel

4. Critical Installation Note

● Horizontal installation ONLY

● Flow arrow must match medium direction

● DO NOT install vertically

Installation, Operation & Maintenance

1. Installation

● Verify model, pressure, size, material before installation

● Clean pipeline to avoid debris jamming the disc

● Tighten flange bolts crosswise; use spiral wound gaskets

● Perform hydrostatic test after installation

2. Routine Inspection

● Check flanges and bonnet for leakage

● Observe for abnormal noise or vibration

● Increase inspection frequency for high-temperature / corrosive service

3. Maintenance

● Clean cavity and guide during shutdown

● Inspect disc and seat for wear; re-overlay if needed

● Check disc lifting flexibility before restart after long downtime

4. Troubleshooting

● Leakage: Check sealing surfaces, gaskets, bolt torque

● Stuck disc: Disassemble, clean, align guide

● Poor sealing: Repair sealing surfaces, check disc return

Applications & Industries

Stainless Steel Lift Check Valves, with their stable structure and strong corrosion resistance, are suitable for:

● Petrochemical: Process pipelines, solvents, oil transportation

● Municipal: Water supply, sewage, chlorinated water treatment

● Power: Auxiliary systems, steam, condensate lines

● Food & Pharmaceutical: Clean media, hygienic pipelines

● Metallurgy & Shipbuilding: High-temperature, corrosive, high-pressure pipelines