Everlasting Blow Down Valve ?

I'm building a 5" gauge Crab to Don Young,s design, the boiler drawing shows the blow down valve on the front of the throat plate, not very convenient placing and it calls for a "everlasting blow down valve" is this a trade name for some fancy automatic valve or is it just a bog standard blow down valve ?.

I'm toying with the idea of moving the valve to the side of the fire box, I've drawn it out but this doesn't look to promising with the wheels getting in the way, can any one give me a bit of advice please.

Stew

There is an Everlasting Valve Company see **LINK** looks as if they use a side to side swinging "cymbal" (ish) shape member to open and close the exit. Blowdown valves are one of thier product lines.  Assuming that style of valve is / was their signature product I guess Don specified something in that style for space and operating rod run reasons. Presumably theory is that moving the sealing element from side to side keeps the innards clean and the sealing edges sharp. Obviously sealing is inherently pressure assisted.

There is a downloadable selection guide in pdf, smallest looks to be approaching 6" diameter and 3" deep for 3/4" pipe so not an off the shelf item. Design doesn't look to be something that scales down well. Even at 5" gauge it has overtones of watchmaking.

Clive.

Edited By Clive Foster on 13/06/2016 19:13:57

Stew

The Everlasting blowdown valve was made by an American company ( as Clive says) and was fitted to most North American locomotives ( also lumber donkey engines). A model one was detailed by LBSC in his book "Shop Shed and Road". His is 7/8" dia and threaded 1/4- 40 for screwing into the boiler. It opens fully with about a 45 deg movement of the operating lever. I have one fitted to my 5" gauge 0-4-0 and it works great. Occasionally dribbles when cold but takes up once hot. Mine is fitted just above the foundation ring at one corner of the backhead. In LBSC's description he shows it fitted to the front just above the foundation ring.

John Purdy

Hello Stewart,

The" Everlasting blowdown valve" as specified by Don Young is a larger version of that described by LBSC in his Live Steam book. The valves were excellent as the operation was by simply a lever and by design the valve was kept on it's face by boiler pressure until operated. In this country Riddles fitted his standard designs with the Everlasting blowdown valve, no doubt made here under licence, the valve being positioned low down on the throatplate and the valve operated by a pull handle. I think Doug Hewson in both of his 5" gauge BR standards, the standard 4 4-6-0 and the standard 4 tank, described the construction and installation of an everlasting type blowdown valve.

I would advise incorporating a similar valve much as Don suggested.

Regards,

Bob Youldon

Thanks for your replies chaps that helps a lot.

I couldn't find LBSC design in Shop, Shed, and Road, its a very old copy I have I think it may be a first edition and its not in there I also have a copy of his Model Locomotive Building book and I can't find it in their also, but I did find it in K.Harris' book Model Boilers and Boilermaking.

Thanks again

Stew

The problem with LBSC's SPEEDY is that the the blow down valve is on the backhead just above the foundation ring, thus preventing a full blowdown unless the loco is pointing up hill by about 20 degrees.
BobH

Hi Stew,

I have the LBSC drawings for the Everlasting blowdown valve for his 3.5"g Britannia. They are in ME 23rd April 1953. If you need copies let me know. (He also specified this type of valve for Maid of Kent, Minx, and Doris).

My edition of LBSC's 'Live steam Book'/'Shop Shed and Road does not include the everlasting blowdown either.

Doug Hewson (now Steve Hudson) does a lost wax casting and drawings for a 5"g version.

The blowdown valve should ideally be situated at the lowest point of the boiler.

Cheers,

Julian

Good afternoon Stewart,

I didn't think I was going mad, in the 1954 edition of "The Live Steam Book" pages 205 - 209 contain drawings and a description of the construction of an "Everlasting" blowdown valve; whilst it is for a 3/4" scale locomotive it could easily be enlarged to suit a 5" gauge locomotive.

A very good description and drawings for a similar valve for a 11/2" scale locomotive appear at http://livesteamt3.blogspot.co.uk/2016/06/everlasting-blowdown-valve.html

Incidentally, I have an early copy of Shops, Shed and Road in which someone has indicated it was published in 1929 and it would appear to have been J N Maskelyne's own copy as he has signed the fly leaf; on the first page there is a note and poem by LBSC, it's signed Curly, Purly Oaks locomotive works, August 1949, also there's a rubbing of his LBSCR cap badge and a rubbing of the numberplate of his little 31/2" gauge single Grosvenor. For the record the "Everlasting" blowdown valve doesn't appear in that edition.

Regards,

Bob Youldon

My 1969 "New de-Luxe Edition" of Shop Shed & Road shows the Everlasting blowdown valve on pages 168-171. I see what you mean by watchmaking though!

Andy

Stewart, Have sent message

Edited By Anthony Kendall on 15/06/2016 13:48:56