Bore size and connection size: keep the information separate
Two numbers on the same page, measured in millimetres, describing entirely different things. Keeping them apart avoids a whole class of wrong comparison.
On an ANYI model page the bore appears as a single figure - 4mm on the XF-35H, 6mm on the QF-10 - and the connections appear as designations, which may also contain a number. Both look like sizes. They answer different questions, and comparing across them produces confident nonsense.
What the bore tells you
The bore is the narrowest passage the gas travels through inside the valve. It governs how fast you can fill or discharge, and nothing else. It does not tell you what the valve screws into, it does not scale with the body size, and two valves with identical connections can have different bores.
If your filling station or your discharge equipment has a throughput requirement, the bore is the line to state in your enquiry. If it does not, the bore is information rather than a constraint.
What a connection designation tells you
A connection designation describes a joint: the thread form, its diameter and pitch, its hand, and in the case of an outlet standard the seat and nipple as well. The number inside a designation belongs to that system of designations. It is not a millimetre figure you can hold up against the bore, even when it happens to look like one.
How to compare them
- Compare bore with boreAnd only where the flow requirement is the thing in question.
- Compare connection with connectionWithin the same designation system. A taper pipe thread and a parallel thread of similar nominal size are not comparable by their numbers.
- Do not infer one from the otherA larger connection does not imply a larger bore, and a small bore does not imply a small fitting.
- State which one your requirement is aboutHalf the ambiguity in valve enquiries disappears when the sender names the quantity they mean.
Two common questions
I need "a bigger valve". What should I send?
Say whether you mean more flow (bore), a different fitting (connection) or a higher pressure rating. Those lead to three different models.
Is the bore the same across a model family?
Not necessarily. It is recorded per exact model, like everything else on the page.