We are your dedicated equipment and parts people.

NH₃ (Anhydrous Ammonia) Safety Relief Valves

NH₃ systems operate under high pressure, and a reliable safety relief valve is essential for protecting equipment, operators, and the environment. Our selection of NH₃ (Anhydrous Ammonia) safety relief valves are engineered to meet industry regulations and provide dependable pressure release when it matters most.


2 products


Our Current Selection of NH₃ (Anhydrous Ammonia) Safety Relief Valves

Why Choose Our NH₃ Safety Relief Valves?

  • Precise Pressure Protection – Opens at an exact set pressure to safeguard tanks and systems.
  • Built to Last – Made from corrosion-resistant materials for tough NH3 environments.
  • Regulation-Ready – Meets ASME and NFPA 58 standards for safe operation.
  • Fits Your System – Available in multiple port sizes for applicators, tanks, and bulk storage.
  • Reduces Product Loss – Prevents accidental ammonia releases, protecting your investment and the environment.
  • Trusted Support – Expert guidance to select the right relief valve for your NH3 operation.

Shop With Mid-South Ag For High-Quality, Reliable Equipment

Choosing the right equipment is non-negotiable when dealing with a product as hazardous and critical as anhydrous ammonia (NH3). At Mid-South Ag, we provide the reliable, certified components you need to protect your operation, your investment, and your people. If you need any assistance with our products, contact our team for more information.

Frequently Asked Question

An NH3 safety relief valve is a pressure-activated device designed to protect Anhydrous Ammonia tanks and lines from dangerous over-pressurization. These relief valves open automatically when the system reaches its set pressure, preventing equipment damage, product loss, and safety risks. They are required on ASME tanks and follow standards outlined in NFPA 58 and the ASME Boiler and Pressure Vessel Code.

Most pressure ammonia relief valves used in NH₃ service should be replaced every 5 years or sooner if exposed to corrosion, damage, or if they have discharged. Regular replacement helps maintain safe operation and ensures compatibility with your tank’s pressure range and gas types.

A safety relief valve protects tanks and vessels from high internal pressure, while a hydrostatic relief valve (sometimes called a hydrostatic relief) protects liquid-filled piping from pressure increases caused by thermal expansion. Both are critical relief devices, but they serve different points in the system.

A vapor relief valve is used on vapor lines and vapor-only systems to maintain safe operating pressure without releasing liquid ammonia. These Vapor Relief Valves are commonly installed in transfer systems, storage sites, and bulk storage applications.

Relief valves are offered in multiple port options such as 1/4" MPT, 3/4", or 1-1/4". Your required port size (or port size A) depends on tank design, code requirements, and flow capacity needs. Always match the valve to your tank manufacturer’s specifications or consult our technical support team.

Currently, we stock Continental NH₃, a leading manufacturer of NH3 (Anhydrous Ammonia) safety relief valves.

Some pressure relief valves are designed for both Anhydrous Ammonia and industrial refrigeration system use, depending on body material (such as stainless steel) and seat type (e.g., synthetic rubber seat, resilient seat disc). Always verify compatibility before installation.

You may also consider replacing related components such as angle valves, ball valves, bleeder valves, needle valves, dip tubes, and gaskets to ensure leak-free operation. For large installations, a relief valve manifold may be required.

The required max PSI and set pressure depend on your tank rating, service environment, and system configuration. Relief valves for NH₃ commonly use a 250 PSI setting, but always confirm with your equipment’s Standard Operating Procedures and tank markings.

Yes. Properly functioning relief valves reduce accidental releases that contribute to greenhouse gas emissions, air pollution, and unnecessary product loss. Using the correct valve and regularly maintaining it supports environmental sustainability and overall system safety.