GCE SAFE-GUARD-1 BV 12 Non-Return Valve for Torches

A compact non-return valve for the torch inlet

The GCE SAFE-GUARD-1 / BV 12 is a one-function safety device: a non-return valve that stops gas flowing backwards into the hose. GCE makes it to its own approved design, and its assembly method avoids soldered or bonded joints. It is suitable for oxygen, acetylene, propane and natural gas, and it works on both nozzle-mix and injector-type torches. The body is no bigger than an ordinary hose nipple, and GCE states that the pressure loss is insignificant, so the set working pressure stays unchanged.

GCE recommends mounting a SAFE-GUARD-1 / BV 12 on the torch inlet for both oxygen and fuel gas, and testing the non-return function at least every six months. It is manufactured in accordance with ISO 5175-2, the standard for non-return valves without flame arresters. Where a flame arrester is required, GCE supplies the SAFE-GUARD flashback arrestors separately.

Technical specifications

Versions and article numbers

The datasheet lists three families: versions with hose nipple and nut, versions without nut, and versions with threaded connections at both ends. Fuel-gas parts use left-hand threads.

Without-nut versions are 0863531 to 0863534 and the twin set 0763568 (G1/4 in and G3/8 in, 6.3/8 mm twin hose). Threaded-both-ends versions run from 0863561 (G1/4 in oxygen) to 0863566 (9/16 in UNF LH fuel). GCE has made the 5 mm without-nut versions obsolete. Choose the hose size to match the hose bore, because the pressure-drop curves differ between 6 mm and the 8 and 10 mm versions.

Use with flashback arrestors and flow conversion

A non-return valve is not a flame arrester. For protection against a flashback travelling into the regulator or supply line use a unit such as the GCE SAFE-GUARD-5 flashback arrestor at the regulator, with the BV 12 at the torch. The GCE flow charts show pressure drop for 6 mm and for 8 and 10 mm hose at inlet pressures from 1 to 15 bar. For gases other than the one charted, multiply the flow by the datasheet coefficient:

What a non-return valve does and does not do

In oxy-fuel work, backflow happens when one gas is at a higher pressure than the other, for example when a nozzle is blocked, a cylinder runs low or the valves are opened in the wrong order. Oxygen can then travel into the fuel hose, or fuel into the oxygen hose, and form an explosive mixture inside the hose. The SAFE-GUARD-1 / BV 12 stops that reverse flow at the torch with a spring-loaded poppet.

It is important to be clear about its limits. As a non-return valve without a flame arrester, it does not stop a flashback flame front and it has no temperature-sensitive cut-off. Where the work procedure or local regulations call for flashback protection, combine it with a flashback arrestor at the regulator outlet.

Typical protection layout

• At the torch: one SAFE-GUARD-1 / BV 12 on the oxygen inlet and one on the fuel gas inlet.
• At the regulator: a flashback arrestor on each line, chosen for the gas and flow.
• Hoses: correctly coloured and rated for the gas, with matching hose size (6.3, 8 or 10 mm depending on version).

Fitting and checking

Identify the gas before installation: fuel-gas versions use left-hand threads, oxygen versions right-hand, which helps prevent mixing the lines. Make sure the flow direction marked on the body points towards the torch. Tighten with suitable spanners and never use oil or grease on any oxygen fitting.

GCE recommends testing the non-return function at least every six months. Also check after any suspected backflow event, after a torch has been dropped, and whenever the valve has been exposed to dirt or spatter. A valve that leaks in the reverse direction, sticks or shows damage should be replaced rather than repaired on site.

Daily operator checks

• Inspect the body and threads for damage and contamination.
• Purge each line separately before lighting the torch.
• Follow the correct lighting and shut-down sequence for the torch type.
• Close cylinder valves at the end of the shift and release pressure from the hoses.

Use in Omani and GCC workshops and sites

Gas cutting and heating are routine in fabrication shops, shipyards, oil and gas maintenance and construction sites throughout the region. Many contractors require backflow protection at both torch and regulator as part of their hot work permit system. The stated temperature range of -30 °C to +50 °C means torches and hoses should not be left in direct summer sun for long periods, since metal surfaces can exceed ambient air temperature.

RFQ checklist

• Article numbers for the fuel and oxygen versions required.
• Connection type: hose nipple with nut, without nut, or threaded at both ends.
• Hose size and thread standard used on the existing torches.
• Fuel gas: acetylene, propane or natural gas.
• Quantities, including spares for periodic replacement.

Documents and quotation

The GCE SAFE-GUARD-1 / BV 12 datasheet is attached under Datasheets & Documents. Torches that use it, for example the GCE X501 Original hand cutting torch, are in our Oxy-Fuel Cutting Equipment category.

For a quotation, send the article number, or the gas, thread, hose size and quantity.