... could someone tell me the difference between a shut off valve and an appliance valve please?

Or perhaps better put, when might I use one but not the other?

 

They appear to me to do the same thing, and Tinternet is less than helpful: a search of images of each shows both types seem to be randomly named (using the HEP20 catalogue - price list as a guide).

 

Maybe they both do the same job: in which case  why prefer and not the other?

The shut off valve tends to be In pipework (pipe in both ends) and a service valve has a thread one end to fit an appliance . This is an appliance valve for a washing machine, pipe in one end and washing machine pipe the other. 

https://www.screwfix.com/p/washing-machine-valve-without-check-valve-15mm-x/51231

 

? Yer a star Joe. Thanks. Ian

I would love to have one with a much larger handle as operating these standard valves (which I probably need to do once in a few years) is a pain. Pretty sure my wife wouldn't be able to turn it. 

1 minute ago, oldkettle said:

I would love to have one with a much larger handle as operating these standard valves (which I probably need to do once in a few years) is a pain. Pretty sure my wife wouldn't be able to turn it. 

this is where a 3D printer could be useful 

Screwfix used to sell ones with a little handle rather than a screwdriver slot, much better.

Here you are : I'm going to fit them @oldkettle for precisely the reasons you give above. My hands are already a mess; and thats only going to get worse with age.

 

As my namesake puts it : We're gonna have to put (me) in a home soon.

 

29 minutes ago, AnonymousBosch said:

Here you are : 

I used these for isolating my hot and cold feeds to my manifolds and they are very good .

I always use full bore isolators as Joe has stated above. In my opinion those things with a little screw in the middle, regardless of what make, always end up leaking.