Carette Stork Leg

[Alan29Participant @alan29]

Hi folks, been racking my brain and “tinterwab” to find “proper” names for the parts on the drive wheel from the piston con rod and slide valve linkages on my Stork leg. New to steam engines, especially this one. Hoping someone can advise.

There is a pear shaped cam whose top lobe connects to the piston linkage. The slide valve linkage has a large circle that houses a flanged boss that is fixed to the pear shaped cam by a tiny screw and rotates eccentrically providing the movement for the slide valve. This boss also locates on the drive wheel axle.
Ive probably confused you all with this description, but can’t see how to add a pic to this new thread…… new to this forum!!

Cheers.

[Alan29Participant @alan29]

Trying to find technical names for parts!!!

[Grindstone CowboyParticipant @grindstonecowboy]

Can't help with the steam engine, but this may help with posting pictures.

Rob

[not done it yetParticipant @notdoneityet]

You could search build-videos or kit-building instructions for names of parts?

[Martin ConnellyParticipant @martinconnelly55370]

Good luck with your search. I worked the engineering industry for many years and parts got nicknames that would mean nothing to people outside of the company. Stick insect, elephant trunk and donkey ears for example. You only need to think about grass hopper engines and stork leg engines to realise it is an old and continuing practice. The military is also good for jargon, look how the Huey or the jeep got named.

Martin C

[Alan29Participant @alan29]

Hi folks thanksd for the comments/info.

This loco I am restoring had the front cover removed which I have just resoldered back on.

Static water test showed no leaks but I want to put a hydraulic pressre test on it. This bodes a few questions…

1. What is the working pressure of a Carette Stork Leg ?

2. What would the test pressure be?

3. Anyone be got any info about diy test rigs / where to get hold of equipment to make one.

The boiler is brass and most of the fittings are through the skin and into internal bosses. However, the water fill is just through the boiler body(no internal boss). Any suggestions on improving the fill port? Maybe an external plate soldered on. There is a pic in my album of the boiler with its fittings. Cheers in advance.

Edited By Alan29 on 28/10/2020 00:45:00

[Martin ConnellyParticipant @martinconnelly55370]

Hydrostatic tests need to be something like 10% above the system safety valve release pressure, can't remember exactly how the Pressure Equipment Directive (PED) is worded I stopped worrying about it when I retired. The issue for boilers is that they work at higher temperatures than is used in the test fluid so some allowance probably has to be used to make the test suit working temperatures.

The pipe pressure test system where I worked had a water treatment plant to remove corrosive salts from the town water supply. The pipe being tested was fitted to the rig and filled with treated water then capped off (or suitable bosses were plugged if available) at the top where the air escaped as they were filled from below. The water pressure was then raised to the required pressure with a pressure intensifier (air pressure on one side of a piston water on the other, different areas so pressure was increased on the small area side) and the water supply locked off. The system was then left for up to 30 minutes to allow temperature stabilisation. At the end of the stabilisation period pressure was monitored with electronic pressure gauges and any leak was apparent due to small leaks causing large drops in pressure. The pipes were also visually inspected during the test as any leaks would show by the appearance of water on the surface or at joints. There was also a mobile system for taking to locations as required. You could also buy (if required) high pressure hand screw driven piston pumps to raise the water to the required pressure (imagine a medical syringe being operated by closing a vice on the plunger). This system was 800psi for the static bench (old design, label on it stated this figure) and a mobile system that went up to 30,000 bar for really high pressure parts such as hydraulic torque wrenches.

In a previous job I also spent some time calibrating and checking pressure gauges with a dead weight tester that had a hand screw driven pump to raise the pressure required.

Martin C

[Roger ClarkParticipant @rogerclark]

Assuming this is a vintage gauge 1 engine the boiler pressure will be similar to the Mamod/Willesco et al 'toy' engines that abound. That will be quite low, in the 20 to 30 lb psi range, would be quite safe to heat it up, with water in, to see if it leaks. You're not going to have destructive explosions, just hisses and sizzles.

A hydraulic test is more likely to damage it rather than prove its safety.

Roger

Edited By Rockingdodge on 28/10/2020 10:14:56

[Brian GParticipant @briang]

Hi Alan

If your loco has the same valve gear as the one in this photo I found on liveauctioneers.com you may find the naming of parts to be a problem as it doesn't resemble full-size practice but appears to use a slotted rod like John Turner's "Caledonia" to rock its expansion link.

I would suggest testing the operation of the safety valve before testing the boiler. If you fill it completely it should start to release water long before reaching boiling. Mark Horovitz says in "A Passion for Steam" and online that his oscillating example runs at 10 psi. Perhaps you could contact the person who posted this video on YouTube earlier this year to find if he can give any advice?

Brian G

Edited By Brian G on 28/10/2020 11:39:04

[Former MemberParticipant @formermember12892]

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[Former MemberParticipant @formermember12892]

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