GORDON SMITH SAFETY VALVE

[chris vine]

Hi Rich,

Sorry, I meant silicon nitride.

EG on ebay here. posted from uk and free post too...
www.ebay.co.uk/itm/272739526762?hash=item3f808ae86a:g:IY0AAOSweatea13k&amdata=enc%3AAQAIAAAA4LmWsNBVBc0HVDzX2iaqX6xFurs83FSosPf3lBtBZUdzpG%2FfP60RhmdzdM2tElzkYRiMgKiHaJ7p4YsEIMR5dyugQzA7y%2Fdmk1p2nJ%2BByZrpqw2%2FzwnMrvEO96T0AFs0sKf053UVN%2BGhZ0IE4EBKP6FrKRjUYfbCMgfv4Ki6%2FymaK5BUnKPpbK%2BVxl%2FeQOhXXO0kRcIxanKpRjyewKwCdS8%2FbvfUcQFwrz%2BB3ESVI68Lula9fEVum2rFvhb1W8Q3TYVIBIJzSt0gcpSXXbUPsU3jXfPjXvCmll7Lw%2FjP60DH%7Ctkp%3ABk9SR-SwwNnzYQ

Chris.

[stevep]

What's a loose end?

[firebird]

Hi Chris

Yes thanks for the info

I'm not in a rush so ordered some from China

10 X 5/16'' and 10 X 1/4'' £9.57.

Bargain

Cheers

Rich

[firebird]

Hi

Thanks also to Kerrin

Steve, I'm not sure what the scientific or medical term is for "loose end" but they should be avoided at all costs

A spell in the shed usually cures them

Cheers

Rich

[steamer5]

Apr 20, 2023 8:14:39 GMT stevep said:

What's a loose end?

What you get when SWMBO hasn’t got a honey do for you! I got a couple of hours in the shop late yesterday!
Now donning his pith helmet & Ducking for cover!

Cheers Kerrin

[firebird]

HI

I tested both the valves on my hydro kit and they hold pressure ok. I have both of them set to 80psi at which point I get water gently fizzing out he valve. If I pump fast I can just about get them up to 83 psi. I'm assuming they will react differently under steam?

I left one of them on the rig over night and has only dropped to 60 psi





Cheers

Rich

[oldnorton]

Sizzling safety valves are part of the steam engine's character, an attribute to be enjoyed.

[JonL]

and really hard to cure!

[Cro]

Apr 20, 2023 13:56:28 GMT oldnorton said:

Sizzling safety valves are part of the steam engine's character, an attribute to be enjoyed.

In some ways, in other ways they ruin your paint and make things rusty, don’t ask how I know…..

[firebird]

Hi
A little man in China sent me these





I have also made a little tool for adjustment





I have fitted the new balls into the valves and they seal ok.

Cheers

Rich

[JonL]

Can I make a suggestion? Your very elegant tool could really use some additional holes between the pins, or you are going to be fighting the upward flowing steam when you try to make minor adjustments.

[firebird]

Hi Jon

Good Idea, didn't think of that

Cheers

Rich

[runner42]

Hi Rich,

nicely made safety valve, I assume that the UK regs doesn't require a locking mechanism to prevent the pressure adjustment from moving?

Brian

[simon6200]

I’ve had the alarming experience of watching the adjustment piece without a locking mechanism spin out under steam pressure faster than you could believe. A little stainless M3 grub through the body and against the thread of the adjuster was a simple lock. Not tight enough to deform the thread, obviously.

[firebird]

Hi

On the original plans for Sweetpea there is no locking ring. The adjuster is quite secure against the spring



Cheers

Rich

[flyingfox]

Greeting, in the current boiler regulations there is a requirement for safety valves to be locked. 11.9
Regards
Brian B

[uuu]

Not quite - section 11.9 is here:

11.9 Safety valves which are found to alter their set position during
operation allowing the uncontrolled release of the boiler contents
shall be fitted with some form of locking device to prevent this
happening.

It does seem like a good idea to have a lock, even if the setting is not "found to alter". On the Sweet Pea design shown, there's an external thread, presumably for a shroud to carry the steam up through the cab roof. If you wanted to incorporate a lock on a Sweet Pea, there might be some way to combine the functions.

Wilf

[stevep]

If the adjuster were made longer (with the inside relieved to compensate), one could presumably fit a locknut above the valve body.

[firebird]

Hi

In the book Jack Buckler suggests that the threads on the outside onto which the extension tube screws could left plain and the tube made a loose fit so that condensate does not build up inside the tube.

I'm sure that I could get a small M3 grub screw through the side. Makes sense to lock it in position.

Cheers

Rich

[Jim]

May 9, 2023 7:19:11 GMT firebird said:

Hi

On the original plans for Sweetpea there is no locking ring. The adjuster is quite secure against the spring


Looking at the drawing above I'd suggest the outer 35/64"x 26 tpi at the top of the valve's body casing is in fact for a locking ring to screw onto. I made similar safety valves for my Burrell with the locking ring having a lip to retain the adjuster.
Personally I wouldn't be without a locking ring.
Jim