Accucraft Edrig Gas Regulator Valve

[mikewakefielduk@btinterne]

I've recently acquired a second-hand Accucraft Edrig. Did the usual thing with a new (to me) loco - dismantled it, cleaned everything up and then re-assembled to see how it runs. All is well except for the gas regulator which is super sensitive - couple of mm movement is all the difference between about to go out and hot enough to threaten the smoke box door.

The problem seems to be wear although I'm not absolutely sure where (no pun intended). Presumably the tapered needle valve, although I've dismantled and cleaned it and there's no sign of scoring.

Anybody got any suggestions other than fitting a replacement gas regulator?

Mike Wakefield

[steamie1]

My Ragleth is super sensitive on the gas tap. I had a Lawley it was too. I wish the thread was finer...

[mikewakefielduk@btinterne]

Thanks for that, maybe its something I'll have to get used to. I don't remember my Ragleth being super sensitive but I no longer have it to compare. Mind you, the Ragleth burner was really noisy - 747 about to take off - while the Edrig is pretty quiet.

I also noticed the poker style gas burner is upside down to the ones in my Regners, i.e. the holes for the flames are at the bottom rather than the top. Seems to work OK though.

Mike

[steamie1]

Tag recommends a stainless steel gauze wrapped on the burner, like the gauze found on a teabag strainer. It has two effects one it glows red and evens out the adjustment and two it quietens down the burner. It must be stainless..

[mikewakefielduk@btinterne]

That's a good idea. Before that though, will fit a replacement gas regulator. I spoke to the nice people on the Accucraft stand at Warley today and was told the early Edrigs were supplied with regulators with too coarse a thread, so they'll change mine for the correct one. Fortunately I only live a few miles from Church Stretton so will pop down there next week.

They also said all Accucraft gas burners are upside down as they want the flame to play on the lowest part of the boiler in case it ever runs nearly dry.

Also, the second hole under the burner flange is for secondary air and there isn't a screw missing.

Mike

[Chris Cairns]

Watch out for the steam oil burning in the smoke box - should come with a H&S warning.

Mine has a chuffer pipe fitted so all the oil ends up in the smoke box which heats up & burns. I'm told by another Edrig owner that they are known for going through the steam oil very quickly and chucking the oil out everywhere. My kitchen disappeared in a blue haze on the last run!

The mesh is to turn the poker burner into a radiant burner which are more efficient for a lower gas setting. Ideally you should use nichrome mesh but that is very difficult to find for sale in the UK - I used some stainless steel mesh on my Merlin Locomotive Works Mamod gas burner which vastly improved its radiant properties. Not had time to convert my Edrig burner yet.

Chris Cairns.

[Gremlin]

A drop of steam oil on the gas and steam regulator O rings helps with fine adjustment

[mikewakefielduk@btinterne]

The Accucraft people said the same about a drop of steam oil on the o ring. Apparently if the o ring is dry it tends to stick in the bore so causing the regulator to spring back slightly when you turn it.

Will fit the new regulator this evening to see if it makes any difference.

The Accucraft people also said there's somebody who supplies a replacement needle valve assembly which screws into the existing regulator bore and provides really fine adjustment.  Unfortunately he didn't have any contact details.

Mike

[philipy]

Mike ,
See Chris Bird's post re replacement regulators
http://gardenrails.myfreeforum.org/abou ... 053a2e0e71

[mikewakefielduk@btinterne]

Thanks for the info, what a coincidence that Accucraft mentioned it to me on the same day. Anyway I think I'll order one and give it a try.

Mike

[DolwyddelanLightRail]

Mine has a chuffer pipe fitted so all the oil ends up in the smoke box which heats up & burns. I'm told by another Edrig owner that they are known for going through the steam oil very quickly and chucking the oil out everywhere. My kitchen disappeared in a blue haze on the last run!

Those who have seen my Edrig in action can vouch for that, I had a comment once that someone thought from a distance there was a coal fired loco running...

[mikewakefielduk@btinterne]

Last night I tried 680 steam oil and there wasn't half as much oil under the loco at the end of a (fairly short) test run on the rolling road. Of course what I don't know is whether the cylinders are still getting properly lubricated.

The guys at Accucraft UK recommend 460 steam oil from Morris Lubricants but I noticed thetraindepartment.com in the US sell 320 weight oil.

Mike

[GTB]

To control excessive oil coming out the exhaust at the start of a run, don't overfill the lubricator. It only needs to be filled up to the level of the steam pipe.

If filled right up to the top of the lubricator, a slug of oil will be pushed into the steam line when the cap is screwed down and more will go in when the throttle is opened, until the oil is down to the level of the hole in the steam pipe. The oil also expands as it heats up, which adds more to the slug.

If careful filling doesn't improve things enough, it would be better to control the oil flow by restricting the size of the hole in the steam line, rather than using thicker oil. The hole can be effectively made smaller with a piece of fuse wire pushed into the hole and then bent to keep it in place.

The thicker the oil, the more power it will absorb in the cylinders and it will take longer to flow through the steam pipe as well, which can increase the risk of carbonisation and a blocked steam pipe.

Whether oil is getting into the cylinders or not can be checked by taking off the cylinder end caps. Check both cylinders, as oil can do funny things at tee fittings and an oily exhaust doesn't guarantee both cylinders are getting the same amount of oil.

Graeme

[steamie1]

I have just fitted this on the Forums advice. Will report back when tested.

[mikewakefielduk@btinterne]

This is a gas control with a finer thread? Did you order it from the US?
Mike

[steamie1]

Yes and I was surprised how quickly it came..22 dollars

[mikewakefielduk@btinterne]

My gas control valve arrived a couple of days ago. Superb service - 6 days from ordering to receipt. Cost of postage from the US only around £4

Anyway, I have to say that purchasers need to be a bit careful if my experience fitting the new insert is anything but a one-off.

OK, background first. As mentioned above in an earlier post, Accucraft had given me a complete replacement gas regulator in case my original was an early one fitted with too coarse a thread. However, when I unscrewed the valve from the housing and compared it with the new one, the threads were identical, so I didn't swap the regulators over.

When the new gas control valve insert arrived from the US I unscrewed the original valve from the regulator body, replaced it with the insert (with a bit of PTFE tape around the outer thread), and tried it out and it worked really well. The gas flow was as controllable as other locos I own.

Having satisfied myself the replacement valve insert worked well I took it out and tried it in the replacement gas valve housing I'd got from Accucraft. To my surprise the new valve insert did not seal in this valve housing, despite being fully screwed all the way in. On examination I found that, although the outside dimensions of the Accucraft valve housings were identical, the second one's internal thread and taper were machined some 2mm lower than the other. In other words, even with the gas valve insert screwed fully down its needle wasn't reaching the taper.

I therefore machined 2mm off the top of the second valve housing body, so allowing the new insert to be screwed in further and so allowing the tapered valve to seal correctly.

I'm guessing the Edrig valve housing may be finished by hand in China rather than using jigs, hence the variation between the two.

Mike

[mikewakefielduk@btinterne]

Here's a couple of photos showing the issue:

The first is of the inner spindles from the Accucraft gas regulator. The shorter of the two is from the original regulator that came with my Edrig and the longer from the second regulator that Accucraft gave me a couple of weeks ago. As you can see the distance between the bottom of the thread and the point of the taper is some 2mm longer on the second compared with the first.



and here's my Edrig showing the gas regulator with the insert from The Train department in place. I've machined 2mm off the top of the regulator's body to lower the insert. There's a soft copper washer as well to make a good gas-tight seal.



Although I've solved the problem for myself it doesn't explain why there's this variation. Given that Accucraft use the same gas regulator on their Ragleth and presumably other locos as well, it could make it quite difficult for The Train department to have one insert that will fit all locos.

Mike

[steamie1]

Ok the train department handle was fitted. Yes the fine control is better but it is slight. It also comes up too short as the handle is very close to the cab...So worth doing but only just.I did put a handle on the original valve post, which sat higher and this was ok for normal use but fine low setting were hard due coarser thread. Now fine slow bleed settings are good, but the handle is hard to reach in running operation. I swopped the handle to have the vertical crank the other side which has helped. It was very tight to free out of the valve post. Overall 6/10.