Expansion vessel - Schrader valve

Well - they exist, but finding one locally might be harder.

"Richard Russell" wrote

any truck parts supplier will sell them, also motorhome type places, commonly used as tyre valve extensions, where you have dual rear wheels, and thus have an awkward job getting the airline connector onto the tyres valves,

you can also get spare tyre valve extensions, mainly for motorhomes that have the spare tyre under the chassis as most vans do, but then have a low hanging body built on the chassis making crawling under to check the spares pressure a bit of a chore,

get it in the post via eBay. Here's one 140mm long but there are lots of sizes listed.

IME an expansion vessel that regularly needs re-inflating will not last much longer and really needs replacing. On some boilers this is easy, on others it means a major strip-down, or removal of the boiler from the wall. P&H engineers, I notice, often abandon the dead internal unit and fit a new outboard EV in some (in)convenient nook or cranny.

swings out of the way if you need to get at the bits behind it.

Sorry that link doesn't seem to work, try-

We were somewhere around Barstow, on the edge of the desert, when the drugs began to take hold. I remember "Richard Russell" saying something like:

Yes, indeed. You can get them from a commercial truck stockist, for extending the valve stems on the inner wheels of truck trailers. I had a couple of them 4" long and I'm sure there were longer ones.