FAQCommon questions.

In Hopeet’s own factory in Taiwan. About 95% of the parts in each valve are machined, cleaned and assembled in-house, and every valve is set and tested on our own benches before it ships.

Yes. Since May 2026 Hopeet holds a Module H1 certificate for Category IV safety valves under the Pressure Equipment Directive 2014/68/EU, issued by EURO CERT (notified body 1128) — the highest level in the directive, and held by no other valve maker in Taiwan. The factory is also certified to ISO 9001 and ISO 14001.

Every valve has its set pressure adjusted and checked on a test bench, and its seat tightness tested to API 527. Its test report and test footage are kept for at least five years.

Enter the serial number from the valve’s nameplate in the Test Report Center at report.hopeet.com.tw. You get that valve’s own report: set pressure, seat tightness and the test curve.

You need the medium (air, steam, gas or liquid), the set pressure, the flow to relieve and the connection size. Enter them in the Valve Selector at selector.hopeet.com.tw for a recommended model and its rated capacity, or email them to sd@hopeet.com.tw and our engineers will size the valve for you.

For low-pressure air, with set pressures of about 10–20 kg/cm², our economical bronze S10 is usually the right choice. For higher pressures or corrosive fluids, choose the stainless FGX series. Not sure? Send us the conditions and we will recommend a model.

Yes. For anything other than air and water we recommend a sealed valve with a soft seat such as PTFE: it seals better, so nothing leaks that could harm people or waste costly gas. If the fluid is hotter than 150 °C, please tell us first.

It depends on whether a little leakage is acceptable. The sealed type is closed at the top, so nothing escapes: use it for high temperatures and for corrosive or valuable fluids. The lever type lets you lift the valve by hand to test it, so it is not 100% sealed: use it for water and other fluids that are harmless if they escape. Its more complex build also makes it a little more expensive.

Yes. Our stainless valves can be made with ANSI, JIS, PN/DIN or other flanges on the inlet, the outlet or both, as you specify.

The standard Y-type control valve we keep in stock is normally closed. If you need a normally open version, please tell us before you order.

Yes. The ASV air vent removes trapped air from server cooling loops. It is SUS316L stainless with FKM seals for PG25 coolant, finished below Ra 0.8 μm, assembled and tested in an ISO Class 6 cleanroom and shipped vacuum-sealed. Its female thread fits UQD quick disconnects.

No, that is normal. Every safety valve starts to release a little just below its set pressure — the initial discharge, at about 97% of the set pressure. A safety valve works like a fuse, not a pressure regulator: its job is to let pressure out before a vessel is in danger.

After a valve has opened at full pressure, debris from the fluid often sticks to the disc so it cannot close tightly. Within safe limits, make it open again with compressed air or water to blow the debris out. If it still leaks, send it back to us for repair or replacement; replacement parts are charged.

Every pressure gauge has its own error, drifts with age and has its own accuracy class, so two gauges rarely read the same. Hopeet sets valves against precision gauges that are calibrated in-house and by an outside laboratory on a regular schedule. If you are still in doubt, send the valve back and we will check it; if it is within tolerance, a small testing fee applies.

Hopeet valves leave the factory with a lead seal on the cap, so the setting can’t be changed by accident. To change it, send the valve back and we will reset and retest it for a small fee. A valve whose seal has been removed is no longer covered by the one-year warranty.

No. The reseating pressure follows from the valve’s mechanical design, so it cannot be set separately.

Yes. Keep the pipework clean so debris cannot damage the valve when it opens. In water service a valve can corrode over time and lose function. We recommend inspecting safety valves at least every six months.

A safety valve is the last line of defence for your plant, machines and pipework. If the pressure rose and the valve opened, debris caught on the disc as it closed can damage it — which means the valve did its job and protected your equipment, however new it is. Safety valves are consumable parts; send it back to us if you would like it repaired.

Standard models are kept in stock as parts and are assembled, set to your pressure and tested before they ship — about three days for a single valve. Some special valves are made to order. For large or urgent orders, please contact us.

Yes. We make valves for special pressures, temperatures and connections, fit your own OEM nameplate, and take on ODM and reverse-engineering work — even for a valve you can no longer find. Send your requirements with the OEM / ODM form at hopeet.com.tw/oem/ or to sd@hopeet.com.tw.

Within Taiwan, orders of NT$5,000 or more (before tax) ship free to the main island and outlying islands by Kerry TJ; smaller orders pay shipping. Abroad we ship by UPS, DHL or EMS and quote the freight with your order.

Unfortunately not. Every safety valve is set to your pressure, and once it has popped its disc may be damaged, so we cannot take valves back. Please check the size, pressure and other requirements carefully before you order.

Yes. Send the valve back to us for repair or inspection, together with the repair request form from our Technical documents page (hopeet.com.tw/documents/). Valves carry a one-year warranty against defects that are not caused by misuse or damage.