Stainless Steel Flange Ammonia Shut-off Valves

Stainless Steel Flange Ammonia Shut-off Valves is a dedicated shut-off and regulating valve specially designed for ammonia medium conveying systems. It is mainly used for tight on-off control and precise flow regulation of liquid ammonia and ammonia gas. The valve controls ammonia efficiently by driving the disc up and down via the valve stem.

Targeting the characteristics of ammonia - strong corrosiveness, high volatility and easy crystallization at low temperatures - the valve is integrally made of corrosion-resistant stainless steel, equipped with J41 standard flanged connection and Type-B dedicated sealing components. Through optimized design, it ensures excellent ammonia corrosion resistance, reliable sealing performance and wide low-temperature adaptability in ammonia systems.

As a key control component for the safe operation of ammonia systems, this valve is manufactured in strict accordance with relevant design standards for ammonia equipment and valves. All materials and structures meet the requirements for ammonia service. It is widely used in fertilizer production, refrigeration, petrochemical, spandex manufacturing and other industrial scenarios involving ammonia transportation. It can be directly matched with existing ammonia pipelines, with convenient installation and stable operation.

Core Product Features (Special for Ammonia Service)

Strong Ammonia Corrosion Resistance

Core parts such as body and stem are made of 304 or 316 stainless steel, in strict compliance with material selection requirements for ammonia service specified in HG/T 20581. It can withstand long-term erosion by liquid ammonia and ammonia gas, eliminate material aging and corrosion leakage, and adapt to industrial-grade ammonia with trace impurities.

Special Sealing Design

Adopts Type-B dedicated sealing structure for ammonia service, matched with fluororubber or special ammonia-resistant rubber seals, together with flexible graphite packing specially for ammonia. It effectively prevents ammonia permeation. Sealing performance meets Grade A of GB/T 13927, with no visible leakage in special sealing tests.

Strong Service Adaptability

Designed temperature range: -40℃ ~ +150℃, perfectly suitable for low-temperature liquid ammonia storage and high-temperature ammonia gas conveying.Outside Screw & Yoke (OS&Y) structure provides visible stem movement for easy on-site operation and inspection.

Outstanding Safety Performance

Electric and pneumatic versions are equipped with explosion-proof actuators, complying with Exd II BT4/CT4 explosion-proof grade, suitable for flammable and explosive ammonia.Flange connections adopt RF and MFM faces, conforming to ammonia pipeline flange standards, further improving sealing reliability and reducing leakage risk.

Easy Operation & Maintenance

Manual type with labor-saving handwheel for smooth opening and closing.Electric and pneumatic types support remote control and high-frequency regulation.Simple structure for easy disassembly and maintenance; wearing parts (seals, packing) can be replaced conveniently, reducing long-term maintenance cost.

Core Technical Parameters

Material Configuration of Key Components

Product Applications

With special anti-ammonia design, reliable sealing and wide service adaptability, Stainless Steel Flange Ammonia Shut-off Valves is widely used in various industrial scenarios involving ammonia transportation, storage and regulation. ● Fertilizer Industry: ammonia synthesis, storage and pipelines, for shut-off and regulation under high temperature and high pressure.

● Refrigeration Industry: liquid ammonia circulation systems in cold storages and refrigeration units, suitable for low-temperature liquid ammonia.

● Petrochemical Industry: ammonia-related reactions, purification and pipelines, resistant to strong corrosive ammonia.

● Spandex Manufacturing: ammonia raw material conveying and reaction systems, for precise flow control.

● Other Fields: ammonia reagent storage, waste gas treatment, pharmaceutical and chemical processes involving ammonia; customizable for specific conditions.

Selection Guide (Precisely Matched for Ammonia Systems)

According to ammonia type and temperature

oLow-temperature liquid ammonia (≤ -20℃): select 316 stainless steel + low-temperature special ammonia-resistant seals to avoid embrittlement and corrosion.

oHigh-temperature ammonia gas (≥ 120℃): ensure seal temperature resistance ≥ 150℃ for stable long-term sealing.

According to system pressure

Select PN10/16/25/40 based on design pressure. For fluctuating pressure, choose one higher pressure class for extra safety margin.

Seal selection

oGeneral ammonia service: fluororubber Type-B seal (cost-effective & reliable).

oSevere corrosion or low-temperature liquid ammonia: must use special ammonia-resistant rubber to prevent permeation.

Actuation selection

oSmall/medium bore, low operation frequency: manual type (easy operation, low cost).

oLarge bore, high frequency or remote control: electric/pneumatic explosion-proof type for safety.

Connection selection

Strictly match on-site ammonia pipeline flanges. MFM is preferred for better sealing performance than RF.

Operation & Maintenance (Ensure Safe Operation)

Operation Notes

● Before installation, verify model, pressure, material and seal type to match ammonia service. Clean oil and impurities inside the body and flange faces. Do not leave grease or acidic substances that may react with ammonia.

● Install according to flow direction mark (low inlet, high outlet). Reverse flow will cause seal failure and serious leakage risk.

● Operate smoothly and slowly. Avoid excessive force on manual valves. For electric/pneumatic valves, check wiring, air supply and explosion-proof integrity before commissioning.

● Strictly prohibit over-pressure and over-temperature operation. Stop immediately for inspection if abnormal noise or vibration occurs.

Maintenance Notes

● Inspect sealing regularly with ammonia leak detector. Tighten packing gland for minor leakage; replace seals immediately if leakage continues.

● Maintenance must be performed after complete pressure relief and medium purging. Never disassemble under pressure to avoid ammonia leakage accidents.

● Use only original ammonia-specified parts (seals, packing) for replacement. Ordinary seals are strictly prohibited.

● Before restarting long-idle valves, check stem movement and seals. Perform ammonia sealing test if necessary. Protect against moisture and dust during shutdown to avoid stainless steel corrosion.