Isolation valves - flow direction not marked?

[Hallsy]

Bought some isolation vales from merchant this morning and unlike others I've bought they have flow direction arrow.

Does this mean they can go either way, or is there a way of telling?

They're 15mm large bore & 22mm std bore.

 

[Softus]

It's likely to mean that they can either way, but are there any markings at all?

If you really want to be sure, then 'phone the supplier and ask them to confirm that the manufacturer says that they're bidirectional.

 

[corgiman]

probably full bore ones so it dont matter

 

[Hallsy]

They have B on them and PN40 ***.

he 15mm ones are large bore, and the 22mm ones look to be large bore as well.