PTFE Regulator

[greasemonkey]

Hi All
Has anyone used PTFE as a regulator face? Ive got to make the regulator for my Simplex and Im just throwing ideas around for a bit of inspiration.

Andy

[havoc]

Not personaly, but I heard some comments from a clubmember who did. He used a facing of ptfe on the regulator. It worked well, but he complained about the ptfe settling to the form of the opening. So it works fine, but if you put it away and the ptfe isn't against something flat, then that form will be embossed into the ptfe. This means it isn't tight next time you use it. It isn't bad, and it adjusts itself after some time.

[Steve M. W]

Hi Andy

I am building a Simplex whats wrong with the regulator as drawn, would welcome any information and any other comments or changes you have made in the construction of your Simplex.

Steve

[clifwalker]

When I constructed a Pansy I used PTFE seals on the regulator. I simply machined out a grove around each of the holes in the facing block and made PTFE rings to suit which stood out slightly proud of the surface. I seemed to work OK.

[steamjohn248]

Why not use SS ball valves they have a perfect seal and progressive delivery we use them all the time and they work a treat.

Steamjohn

[greasemonkey]

Hi SteamJohn
A ball valve would have been my first choice but I havent got enough space to get one in without a lot tight bends in the main steam pipe.

Andy

[steamjohn248]

Hi Andy

Difficult to describe but easy to make. If you can get me your E mail address I'll send you some photos. Basically the steampipe goes into a Tee with the stem pointing up into the dome on which you screw the ball valve then a pipe from the ball valve into the top of the dome. The end of the tee opposite the steam pipe takes a blank plug with a bush for the end of the regulator rod . two arms on a cross piece on the end of said rod up to a cross arm on the valve stem and bingo. All in SS of course.

Steamjohn

[Steve M. W]

Hi Steamjohn

Sounds interesting any chance I could see photos, was yours in a Simplex?

Steve

[ridleyian]

Me also please.
Where did you source the ball valve, and what sort?
Regards
Ian

[greasemonkey]

Hi SteamJohn
I understand what you mean, but I am having difficulty working out how to get it into the confined space of a Simplex boiler without a fairly major redesign of the boiler structure and all the attendent problems that involves.
If I was to move the regulator operating rod externally, acting through the side of the boiler barrell then it would be fairly straight forward, but to get it in without some tight 90 deg bends doesn't at first seem straight forward. Ive sent you a PM with my email address.
cheers

Andy

[frank]

Hi,
Have tried PTFE in a disk type regulator that I made to replace a Greenly type regulator in a 7.25 loco. The PTFE is a disk pressed in to a bronze housing well supported at back. The steam passage through the PTFE disk is a radial cut hole equal in width to the largest hole in the regulator disk, this disk has a series of holes, starting at a 1mm dia and opening to 4mm dia, regulator disk rotates through 90. control is very smooth with very fine control of loco at low speed.

[steamjohn248]

Hi to everyone that was interested in the use of SS ball valves as regulators. If you send, or have sent me your E Mails I will post 4 photos that will I hope give the idea. it is always a case of back of a fag packet then make it fit so no drawings I'm afraid and 7 1/4" is the smallest that my spade like hands can manage. I would assume that if we could get a 3/4" bsp valve in a 7 1/4" boiler you could get a smaller valve in a smaller boiler using the same method.

Steamjohn

[gwrfan]

Thanks SteamJohn,

looks a very interesting project. Something for next winter I think, LOL.

Geoff in rain-lashed Cornwall

[greasemonkey]

Thanks SteamJohn
I'm going to need a small valve but I think I can make it work!!

Andy

[Steve M. W]

Andy

RS Components and Air Products list all types & makes of ball valves, I used two from RS for my boiler test rig.
The RS site will have tec data for the valves make sure that they will stand steam on that they are rated to the pressure you need.
My only connection is as a customer

Steve

[martyn]

This train of thought has made me look at the feasibility of installing a ball valve for the regulator on the Holmside I am building. The main issue is physical room to fit the valve into the boiler or in the dome. I know people have installed ballvalves as smokebox regulators. On the slightly technical side, would the bore of the ball valve (the actual ball) have to be matched to the steam supply pipe bore. Looking at Holmside I may be looking at a 1/4" or 3/8" BSP valve. I also would suggest checking that the valve you are purchasing is rated for pressure and temperature you are working at. As I am sure different grades of PTFE are used according to what the valve is used for. I suppose putting it simplistcally get a good quality valve suitable for steam. Some valves also have cheap brass bodies, so I agree stainless would be good.

[steamjohn248]

As I have pointedsaid in the E Mails I have sent with the photos of the set up we have used on several locos to those who have asked for them, As Steve says, you have to get the right valves for the job, We use the Flowtech range and they set out quite clearly the duty for which the various valves are suitable. Re Martyns comments we use the same size valve as the bore of the steam pipe. Since we got a 3/4" valve in a 7 1/4" Baldwin I would have thought a 1/4" or 3/8" would have been no problem in a Holmside. If you want to consider our set up Martyn I can E Mail you the sceme

John.

[martyn]

John re your reply above, yes I would be interested in some pics can you email me on [e-mail]. I was looking at some valve catologes, saw some interesting 90 deg full bore ball valves, not 3 way. I assume the valve fitted to your Baldwin is stainless, is it screwed to a bronze steam pipe, if so have you witnessed any problem with reaction between the two metals? thinks it called 'galvanetic reaction'.