Regulator Accessories FAQs
Straight answers to the questions people ask most about flowmeters, cylinder connectors, adaptors and other regulator accessories.
How do I read a flowmeter correctly?
A flowmeter has a small ball or float inside a tapered tube, and the ball rises as the gas flow increases. Mount the flowmeter upright, because it will not read correctly if it is tilted, and set the flow with the torch trigger pressed so that gas is actually moving.
The maker's instructions show which part of the ball to read against the scale, often the top of it. Look at the scale straight on, not from above or below, to avoid reading it wrongly. Readings are usually in litres per minute.
Why is the flow at my torch different from the flow on the flowmeter?
The flowmeter only tells you what is leaving the regulator, not what arrives at the nozzle. Leaks in the hose or fittings, a blocked or partly blocked nozzle, a long or kinked hose, and a damaged gas diffuser can all make the real flow at the torch different from the setting.
A draught can also blow the gas away from the weld even when the flow is right. If welds show porosity despite a sensible setting, measure the flow at the nozzle and check the whole gas line for leaks.
What is a nozzle flow tube and how do I use it?
It is a simple test tube that fits over the torch nozzle so you can see how much gas is really coming out at the point of welding. You press the torch trigger without striking an arc, read the flow from the tube, and compare it with what the flowmeter shows.
It is a quick way to find leaks, blockages and wrong settings without welding a test piece. It suits MIG and TIG torches, and it is worth checking after changing a hose, a torch or a nozzle.
Why do I need an adaptor between some cylinders and my regulator?
Different gases use different cylinder outlet connections, partly so that regulators cannot easily be fitted to the wrong gas. An adaptor allows a regulator made for one connection to fit a cylinder with another, for example when a regulator made for one type of shielding gas is used on a cylinder with a different outlet.
Use only an adaptor made for the job and compatible with the gases involved. Never force a thread, never use makeshift fittings, and keep oil and grease away from the connection. If it does not fit easily, stop and check that the gas and regulator are the right pair.