|Brian Abbott||23/06/2019 20:53:12|
408 forum posts
Does anyone know where i can find a drawings for a miniature quarter turn isolation valve ?
Edited By Brian Abbott on 23/06/2019 20:55:51
|Brian Sweeting||23/06/2019 21:28:53|
|399 forum posts|
Are you looking for construction drawings or layout drawings, also what size miniature?
Basic valve layout/data .... **LINK**
Edited By Brian Sweeting on 23/06/2019 21:29:20
|Brian Abbott||23/06/2019 21:41:37|
408 forum posts
I need to make a replacement injector isolation valve, many of the comercial places make them but i need one with a flane mount, what i am after is a design i can adapt.
Edited By Brian Abbott on 23/06/2019 21:42:36
|Nigel Graham 2||23/06/2019 21:56:53|
|461 forum posts|
Note that the link opens the details for the sort of valve common on plumbing systems, and these are very simple but highly restrictive to flow.
I sectioned one recovered from 15mm plumbing, to see if it's possible to make a miniature version, and found the port through the ball is half the pipe bore, so one-quarter cross-sectional area!
The operating spindle has a screwdriver-like tip that engages a shallow slot cut across the ball (verify the orientation before slotting).
The spindle is captive by a shoulder, so the valve is assembled by inserting the spindle from inside, then putting in the far O-ring seating, the ball itself turned to the slot engages, the near O-ring then a special circlip that locks into a groove in the valve wall.
A friend in the plumbing-trade vouched for the restriction they offer, but said full-flow versions are available.
It ought be possible to make full-flow versions for much smaller pipe sizes; though rather fiddly to machine. I'd use a manufactured bronze or stainless-steel ball, but I don't have a ball-turning attachment. Besides, it is likely to be of greater accuracy and sphericity than I'd hope to achieve!
To replace the circlip with something easier I'd be tempted to use a thin push-fitted sleeve trapped by the end-fitting or union, but beware the risk of losing the internal components when disconnecting the fitting.
Alternatively look on the boiler-fittings drawings for almost any miniature steam locomotive or traction-engine. The quarter-turn valves on these are usually plug-cocks, but you should find a design you can adapt to your needs.
|duncan webster||23/06/2019 23:12:18|
2335 forum posts
I'll send you one tomorrow when I can prise SWMBO off the other computer. you'll have to pm me your email address
|Paul Lousick||24/06/2019 07:39:04|
|1283 forum posts|
Globe valves and ball valves can also be used for controlling steam supply to injectors. If you need a flanged type valve, a commercially available valve could be modified by screwing or silver soldering onto a flange.
|Brian Abbott||24/06/2019 08:18:28|
408 forum posts
Duncan, will drop you my email address.
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