Micro-resistance slow-closing check valve

Water system check valves are mainly used for clean water, hot and cold circulating water, domestic water supply and industrial water system, widely used in building water supply and drainage, HVAC, fire fighting and industrial water treatment and other fields. It is suitable for normal temperature and pressure to medium pressure working condition, and the working temperature range is generally from 0℃ to 120℃. Its function is to prevent backflow, protect pumps and system equipment, and ensure the safety of water quality. The valve relies on media pressure to open and close automatically, compact structure, opening and closing sensitive. Commonly used materials are ductile cast iron, brass, stainless steel, etc., the sealing surface can be rubber, PTFE, etc., good corrosion resistance, easy maintenance.

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Micro-resistance slow-closing check valve

Model: HH47X

Subtitle：Slow-closing butterfly check valve

The Micro Resistance Slow Closing Check Valve is a large diameter, high performance check valve designed to prevent backflow and mitigate water hammer effects in high flow systems such as water supply networks, power plants and industrial pipelines. The valve utilizes a butterfly flap design and external hydraulic cylinders to ensure smooth, controlled closure, which eliminates pressure fluctuations and protects critical base...

Tags:Water Hammer Elimination Check Valve

Classification:Water system check valves, Butterfly Check Valve

Working conditions:waterwork

Product Overview

The Micro Resistance Slow Closing Check Valve is a large diameter, high performance check valve designed to prevent backflow and mitigate the effects of water hammer in high flow systems such as water supply networks, power plants and industrial pipelines. The valve utilizes a butterfly flap design and external hydraulic cylinders to ensure smooth, controlled closure to eliminate pressure fluctuations and protect critical infrastructure.

Available in ductile iron, carbon steel or stainless steel, the valve can handle large quantities of water, oil or gas and minimize pressure drop. Its hydraulic slow-closing mechanism (adjustable from 5 to 60 seconds) provides precise control of closing speed and is ideal for applications where effective protection against water hammer is required.

Main characteristics

Butterfly valve flap design: Large diameter butterfly valve flaps (up to DN2000) ensure low resistance to flow, with a Cv value of ≥10,000 (DN1000). Suitable for high flow systems such as pumping stations and water treatment plants.

Hydraulic Slow Closing Mechanism: An external hydraulic cylinder controls the butterfly valve flap closing speed (adjustable from 5 to 60 seconds). Water hammer is eliminated by gradually reducing the flow rate before sealing.

Durable construction: Valve body material: ductile iron (EN-GJS-400-18), carbon steel (ASTM A216 WCB), or stainless steel (ASTM A351 CF8M). Butterfly valve flap and seat material: stainless steel (316/304) with EPDM or NBR seals for long-term reliability.

Low maintenance: self-lubricating bearings and corrosion-resistant coatings extend service life. Hydraulic cylinders are easy to inspect and maintain.

Compliance: Meets AWWA C508, EN 1074 and ISO 5208 for water and wastewater applications.

Product Advantages

Waterproof Hammer: Hydraulic slow-closing mechanism eliminates pressure fluctuations.

Energy saving: low resistance to flow reduces pump energy consumption.

DURABLE: Rugged construction and corrosion-resistant coatings ensure a long service life.

Easy maintenance: external hydraulic cylinders can be quickly checked and adjusted.

Comparison with standard check valves

specificities	Micro-resistance slow-closing check valve	Standard Check Valves
Closure mechanism	Hydraulic cylinder (5-60 seconds)	Spring or gravity (less than 1 second)
Water hammer control	Good (eliminates pressure fluctuations)	Poor (may cause water hammer)
throughput capacity	High (Cv ≥10,000 at DN1000)	Medium (Cv ≤ 5,000 for DN 1000)
appliance	Large-diameter, high-flow systems	General industrial systems

Medium of use

Water/hot water

working condition

waterwork

summarize

The Micro-Resistance Slow Closing Check Valve is a robust, high capacity solution for preventing backflow and mitigating the effects of water hammer in large diameter pipelines. Its butterfly flap design, hydraulic slow-closing mechanism and features that comply with international standards make it ideal for use in water supply networks, wastewater treatment plants and industrial systems. The valve combines energy efficiency and reliable performance to ensure the safety and longevity of critical infrastructure.

Product Parameters

Nominal diameter	DN200 to DN2000 (8" to 80")
Nominal pressure	PN10 to PN25 (EN 1092) or Class 150 to Class 300 (ASME B16.34)
Applicable temperature	-10°C to 120°C (EPDM seals) / -20°C to 80°C (NBR seals)
Valve Material	Ductile Iron (EN-GJS-400-18), Carbon Steel (WCB), Stainless Steel (CF8M)
Valve material	Ductile Iron (EN-GJS-400-18), Stainless Steel (316/304) with EPDM/NBR inlays
sealing material	EPDM, NBR or PTFE for zero leakage
connection method	Flanges (EN 1092, ASME B16.5)
Closing time	Adjustable: 5-60 seconds