Two connection designations, one valve: reading what the factory recorded

A cylinder valve sits between two threads. One enters the cylinder neck. The other accepts the regulator, the filling connection or the hose. Every exact factory model ANYI publishes carries both of them, recorded in the notation the factory itself used.

That last point matters more than it sounds. On the XF-35H the two recorded designations are G5/8 and PZ27.8/25E. On the CGA320A they are 3/4-14NGT and CGA320. On the XF-05B, W21.8x1/14-LH and PZ27.8/25E. On the QF-10, PZ27.8 and G3/4. Each pair describes the same valve from two ends, in two different conventions, and a designation that is routine in one market can be unfamiliar in another.

What a recorded designation does and does not tell you

• A designation names a thread, not a sideA thread form tells you the profile, the diameter, the pitch and the hand. It does not, by itself, say whether that thread goes into the cylinder or faces the regulator. On some pairs an experienced buyer reads the roles immediately; on others the pair is genuinely ambiguous, and ANYI does not publish a guess.
• Taper and parallel are different fitsA taper thread such as 3/4-14NGT seals on the thread flanks as it tightens. A parallel thread such as G3/4 or G5/8 does not, and depends on a separate sealing arrangement. The two are not interchangeable even when the nominal size looks similar.
• An outlet standard is not a thread specificationCGA320 names a complete connection - thread, seat form and nipple - defined by a standard, so that a regulator built to it mates correctly. It is recorded alongside the thread designation, not instead of it.
• -LH marks a left-hand threadIt appears on the fuel-gas side of the range: W21.8x1/14-LH on the XF-05B for hydrogen, and 22.91x1/14-LH on the QF-15G for acetylene. A left-hand thread is a safety convention, not a variant to be substituted with a right-hand one of the same size.
• The bore is a separate factThe nominal bore recorded for each model - 4mm on the XF-35H, CGA320A and XF-05B, 6mm on the QF-10 - governs flow, not fit. A valve can connect correctly and still be the wrong choice for your filling or discharge rate.

Why the orientation is confirmed rather than inferred

ANYI publishes each model with the values the factory recorded for it, without conversion or reinterpretation. Where the factory note has no confirmed English description yet, the specification table says so instead of substituting a translation that might change the meaning of a thread.

The same discipline applies to orientation. Which of the two designations is the cylinder side and which is the outlet is confirmed with the factory for the exact model before quotation. It is not inferred from the order the values appear in, and it is not carried across from another model in the same family. Models in one family are not automatically interchangeable.

What to send so the comparison is quick

Send the working pressure of your cylinder, the two connections you need and, if it matters to your process, the nominal bore. If a safety device is required, say so: its setting is an exact-model fact and is confirmed for the model you choose.

Photographs help more than any description. A picture of your current valve from several sides, one of the markings cast or stamped into its body, and one of each connection let our team compare it directly against the factory records, rather than working from a designation that may have been transcribed along the way.

Questions we are asked about connections