Pressure Relief Valves

A pressure relief valve is an essential device in many systems where pressure must be controlled to prevent equipment failure. By opening at a predetermined set pressure and releasing excess flow, a relief valve ensures that system pressure does not exceed safe limits. At Process Systems, we stock a range of bronze and 316 stainless steel designs, available with closed caps or easing gear. These relief valves are designed for industrial use across air, gas, oil, and liquid applications, but are not for safety relief applications where certified safety valves or coded devices are required.

Our pressure relief valves are manufactured in accordance with relevant industry standards, providing reliable operation and long life when correctly installed and maintained. With sizes from ½" to 2" BSP and a pressure range from 2 to 20 bar, they are suitable for general process protection across many industries in Australia. 

Get free shipping on pressure relief valves and our entire range of valves Australia-wide when you order online. Shop now! 

Why use a pressure relief valve?

In any pressurised system, whether handling gas, oil, steam, or liquid, excessive pressure can lead to catastrophic failure. A pressure release valve provides the last line of protection by venting to atmosphere or downstream until outlet pressure is restored to safe levels.

Relief valves are designed to:

• Protect equipment and piping against excessive pressure
• Maintain stable system pressure during process upsets
• Prevent damage to storage tanks, pressure vessels, and ancillary valves
• Handle a wide variety of fluids and temperatures in industrial service
• Provide smooth operation and reliable reseating so the valve closes once the set point is achieved

While a safety valve reacts instantly and fully to an overpressure event, a pressure relief valve opens gradually at the preset pressure and modulates as pressure drops, ensuring control and consistent protection.

Types of pressure relief valves

Process Systems offers four main designs, manufactured to deliver performance and durability across different applications:

• Bronze pressure relief valves – Compact and cost-effective, with 316 stainless steel internals for corrosion resistance and long operation. Available in closed cap or easing gear types.

• Stainless steel pressure relief valves – All 316 stainless steel body and seat with PTFE or RPTFE seals, built to withstand harsh environments, corrosive fluids, and higher temperature ranges.

• Closed cap models – Provide secure installation where tamper resistance is required, keeping the device safely sealed once the set pressure is calibrated.

• Easing gear (lever) models – Allow manual lift testing to verify correct operation and compliance with site procedures. Ideal where frequent functional checks are part of maintenance schedules.

Other relief products available on request include vacuum relief valves for storage tanks and excess flow devices for specialised systems.

When to use a pressure relief valve

Pressure relief valves are commonly installed to protect process equipment in:

• Steam boilers and hot water systems (excluding coded safety relief duties)
• Storage tanks handling air, gas, or oil
• General plant piping where backpressure or blockage could affect safe operation
• Process skids in the defence, mining, and chemical industries
• Systems carrying fluids that must be discharged safely when limits are exceeded

Because of their adaptable design, relief valves can be used in line with other valves or as standalone protective devices. Each valve operates as an independent safeguard, making them vital to plant safety and compliance.

Installing and maintaining your pressure relief valves

To ensure proper operation, pressure relief valves must be installed in the correct orientation with clear discharge paths and no obstructions. Always follow the manufacturer’s instructions and install in accordance with local codes and industry standards.

• Confirm inlet and outlet connections match the line size
• Install in vertical position unless otherwise approved
• Ensure the seat and spring are free from damage during handling
• Verify all bolts and fittings are secure and properly torqued
• Tag and seal the valve after setting to avoid tampering
• Schedule annual testing and inspection to maintain compliance

When installed correctly and serviced as recommended, a Process Systems pressure relief valve can deliver many years of dependable operation, even in tough process environments.

Why choose Process Systems?

With over 30 years of supplying engineered valves, Process Systems ensures your plant has the protection it needs against excessive pressure events.

• Bronze and stainless steel relief valves manufactured for strength, durability, and compliance
• Options for closed cap or easing gear with lift testing capability
• Same-day dispatch across Australia from local stock
• Free freight on qualifying online orders
• ISO 9001 certified quality system
• Experienced team available to assist with selection, sizing, and installation guidance

Order pressure relief valves online for free shipping Australia-wide

Browse our range of bronze and stainless steel pressure relief valves today. Whether you require a closed cap device for tamper resistance or an easing gear model for in-line testing, our catalogue provides options suited to a wide variety of industrial applications.

Shop online now or contact our team to discuss the most suitable valve for your system.