Name: Pressure Systems Pty Ltd
Address: 35 Sir Laurence Drive, Seaford, VIC, 3198, AU
Telephone: +61 3 9776 9477

Question 1

What's the difference between a safety valve and a pressure relief valve?

Accepted Answer

Although the terms are often used interchangeably, they describe devices designed for different service conditions: Safety valves are typically used for gas, vapour, or steam service. They open with a sudden "pop" action when set pressure is reached, releasing media rapidly to protect the system. Pressure relief valves are used for liquid service. They open gradually in proportion to the overpressure, providing modulated relief. Many modern devices — referred to as PSVs (Pressure Safety Valves) — combine both behaviours and can be specified for either fluid type. The terminology used on a datasheet depends on the manufacturer and the regional standard. If you're unsure which type your application needs, contact our sales engineers with your operating conditions and we'll recommend the right valve.

Question 2

How often should my safety valves be tested?

Accepted Answer

We certify safety valves on a 12-month interval. To keep your certificates current, book a retest each year before the previous one expires. The maximum interval between tests depends on the pressure equipment the valve protects. AS3788 sets these limits: Steam boilers: annual (required) Compressed air and process vessels: every 2 to 4 years (recommended) LPG and static storage tanks: every 2 to 10 years (recommended) Pressure piping: every 5 years (external) (recommended) Transportable vessels (LPG, ammonia, chlorine): every 1 to 2 years (recommended) Most customers stick with annual testing. It keeps certifications valid for insurers and inspectors, and catches problems early. Shorter cycles apply for corrosive, dirty, or high-cycling service, harsh environments, or where your insurer requires it. Not sure when your valves are due? Send us your asset list and we'll work out a schedule.

Question 3

How do I get a quote?

Accepted Answer

Three ways to ask: Click Request Quote on any product page. The form pre-fills with the product details. Use the contact form for general questions or non-product enquiries. Email or phone us directly: sales@pressuresystems.com.au or +61 3 9776 9477. To help us turn around an accurate quote, include: Application (set pressure, application medium, required relief capacity, operating/releiving temperature, required material) Quantity required Required-by date Any preferred brand or model Compliance requirements (ISO, API, AS standards etc.) Quote lead times are subject to enquiry complexity. We strive to give an answer back within 24-48 hours. For urgent enquiries, we recommend calling us.

Question 4

Do you supply test certificates with new valves?

Accepted Answer

We offer two certificate options on new valves, supplied as a quoted item at the time of order: AS 1271 certificate — pressure test only AS 1271 + API 527 combined certificate — pressure test plus seat tightness test Certificates are not included by default. If your application requires documentation, specify which certificate type you need when requesting a quote and we'll include it in the pricing. The absence of a certificate is not an absence of testing. Every valve we dispatch is verified during workshop processing. The certificate is the formal documentation of that testing — we only distribute it when you've requested it at quotation. Certificates are issued digitally under our ISO 9001:2015 quality management system, with results traceable to NATA-calibrated test equipment. Need certification for a new valve? Include the certificate type with your enquiry and we'll quote the appropriate package.

Question 5

What information do you need to size and select a safety valve?

Accepted Answer

To size a safety valve accurately, our sales engineers work through your application's operating and design conditions against API 520 Part I. Send us the following with your enquiry: Process conditions Vessel Maximum allowable working pressure (MAWP) Fluid type (gas, vapour, liquid, two-phase, steam, etc.) Composition or specific service (e.g. natural gas, water, hydraulic oil, ammonia) Operating temperature and pressure Design temperature and pressure Required relieving capacity (mass or volumetric flow rate) Allowable overpressure (% above set pressure) Back pressure conditions (constant/variable superimposed, built-up) Mechanical and installation Set pressure required Inlet and outlet connection type and size (flanged, threaded, welded; ANSI/AS/DIN rating) Orientation (vertical, horizontal) Mounting and access constraints Compliance and material Applicable code (AS 1210, ASME Section VIII, PED, etc.) Material specification (body, trim, spring, gasket) Special service requirements (NACE MR0175, oxygen-clean, food-grade, low-temperature) Required certifications (e.g. CE/PED, ASME UV stamp) Application context Industry and service description Brief description of the protected equipment Any preferred brand or model Once we have this, we'll work through the sizing calculation, recommend a suitable valve from our manufacturer range, and confirm availability and lead time. The end user (process or plant designer) remains responsible for confirming the final selection against the application's design basis per AS 1210. Submit a Request Quote with these details or email sales@pressuresystems.com.au.

Mon–Thurs	8.30am–4.30pm
Fri	8.00am–4.00pm
Sat–Sun	Closed

Pressure Relief & Safety Valves

Safety & Relief Valves (59)

Aquatrol 140 Series Atmospheric Discharge Safety Valve

Aquatrol 563 Series ASME Section I Steam Safety Valve

Aquatrol 573 Series Safety Relief Valve

Aquatrol 69 Series Liquid Relief Valve

Aquatrol 740 Series ASME Section VIII Div.1 Safety Relief Valve

Aquatrol 741 Series Safety Relief Valve

Aquatrol 742 Series Safety Relief Valve

Aquatrol 743 Series Safety Relief Valve

Goetze Series 410 Safety Valve

Goetze Series 412 Atmospheric Discharge Safety Valve

Goetze Series 417/617 Overflow & Pressure Control Valve

Goetze Series 418/618 Overflow & Pressure Control Valve

Goetze Series 430/630 Overflow & Control Valve (Straight-Through)

Goetze Series 431/631 Overflow & Control Valve (Flanged)

Goetze Series 453/853 Overflow & Pressure Control Valve (Handwheel)

Goetze Series 601 Pressure Relief Valve (Lever & Weight)

Goetze Series 612 Pressure Relief Valve (Double Lever)

Goetze Series 628 Pressure Relief Valve

Goetze Series 810 Atmopsheric Discharge Safety Valve

Goetze Series 812 Atmospheric Discharge Safety Valve

Herose 06205 Series Atmospheric Discharge Safety Valve

Herose 06217 Series Atmospheric Discharge Safety Valve

Herose 06388 Series Cryogenic Safety Valve

Herose 06C02 Series Atmospheric Discharge Safety Valve

Herose Type 06370 Brass Safety Relief Valve

Herose Type 06380 Brass Safety Relief Valve

LESER Series 441/442 DIN High Performance Relief Valve

LESER Series 447 Critical Service Safety Relief Valve

LESER Series 526 API Safety Relief Valve

LESER Type 424 Steam Generator Safety Valve

LESER Type 431/433 Modulate Action Safety Valve

LESER Type 431/433 PN 160 High Pressure Modulate Action Valve

LESER Type 437 Compact Safety Valve

LESER Type 438 Compact Safety Valve (O-Ring Disc)

LESER Type 439 Compact Safety Valve (Soft Seal)

LESER Type 440 Flanged Heating Safety Valve

LESER Type 441/442 ANSI High Performance Safety Valve

LESER Type 441/442 Full Nozzle ANSI Safety Valve

LESER Type 441/442 Full Nozzle DIN Safety Valve

LESER Type 444 ANSI Stainless Steel Safety Valve

LESER Type 444 DIN Stainless Steel Safety Valve

LESER Type 447B Conductive PTFE-Lined Safety Valve

LESER Type 455/456 High Pressure Safety Valve

LESER Type 457/458 High Pressure Nozzle Safety Valve

LESER Type 459 HDD Ultra-High Pressure Safety Valve

LESER Type 459 Medium Capacity Safety Valve

LESER Type 460 Threaded Heating Safety Valve

LESER Type 462 HDD High Pressure Safety Valve (O-Ring Disc)

LESER Type 462 Medium Capacity Safety Valve (O-Ring Disc)

LESER Type 481 Clean Service Safety Valve

LESER Type 483 Clean Service Aseptic Safety Valve

LESER Type 484 Container Clean Service Safety Valve

LESER Type 485 Pipeline Clean Service Safety Valve

LESER Type 488 High Capacity Clean Service Safety Valve

LESER Type 811 Pilot-Operated Safety Valve (Pop Action)

LESER Type 814 Dual Outlet Pilot-Operated Safety Valve (Pop Action)

LESER Type 821 Pilot-Operated Safety Valve (Modulate Action)

LESER Type 824 Dual Outlet Pilot-Operated Safety Valve (Modulate Action)

Taylor 8250 Series Relief Valve

Frequently Asked Questions

What's the difference between a safety valve and a pressure relief valve?

How often should my safety valves be tested?

How do I get a quote?

Do you supply test certificates with new valves?

What information do you need to size and select a safety valve?