boiler plumbing

[dwkoski]

I installed the boiler on it's bedding last week and am about to start the plumbing. As I have never done this before I have more than a few questions. The Wisconsin Historical Steam Engine Association is putting on a steam school at the end of the month and I hope to attend and pick up some assistance. In the meantime, i would like to get started on ordering some of the parts I will need. I have a Tiny Power M side crank and a Lund Machine VFT boiler. Jeff has supplied me with the sight glass. Most of the boiler fittings are 3/4". I need at least one (I was thinking of two) pressure relief valves, three try cocks, feedwater inlet fittings, a pressure gauge and outlet fittings as well as throttle and shutoff valves. Also a blowdown valve and fittings for the whistle and exhaust plumbing from the engine. I plan on using schedule 80 seamless steel. Any suggestions on parts sourcing, specific items, and installation tips would be appreciated. Has anyone ever used a flexible connection at any point between the boiler and engine?

[fredrosse]

"I need at least one (I was thinking of two) pressure relief valves" One will certianly do, get a steam rated valve, with affixed lead sealing wire, to certify settings have not been tampered with.

"feedwater inlet fittings, a pressure gauge and outlet fittings as well as throttle and shutoff valves." Get steam rated valves, marked 150 SWP (indicating 150 psig Steam Working Pressure), or 125 SWP, or 100 SWP, etc. The valves' rating must meet or exceed the maximum allowable working pressure, generally the safety valve setpoint for direct boiler steam and water connections. Many of these items are available on e-bay for low prices, and USA brand names such as Crane, Jenkins, Nibco, Walworth and others.

"valve and fittings for the whistle " Same rating system as other valves, however whistle valves are expensive compared to other types.

"exhaust plumbing from the engine" Steel or copper light wall tubing is OK here, provided there are no valves that could result in pressure buildup in the exhaust. Automotive radiator hose and commom hose clamps are OK

"I plan on using schedule 80 seamless steel." That is very good, but ASTM A-53 ERW Schedule 80 piping is certianly adequate, at about 10% - 20% of the seamless piping prices.

"Has anyone ever used a flexible connection at any point between the boiler and engine?" Stainless steel braided flexable piping pieces, about 12 to 18 inches long, are a good selection to allow flexability between boiler and engine. Available from W.W. Grainger, or McMaster Carr, among others. Check pressure/temperature ratings on these to meet or exceed your limits. Many steam launches use these, and a 90 degree bend in the fitting can eliminate all kinds of expansion/contraction and vibration problems, although other configurations can work just as well, provided the flex hose will not get pulled in tension while underway.

[artemis]

I would strongly recommend that you wait until you've completed the steam school to go shopping. You'll probably associate with many others, some of whom will know where you can buy quality steam items at reasonable cost and nearby.

I ALWAYS buy pipe, valves, fittings that are made in the USA or Canada. I was a licensed general contractor and many times I bought materials from Home Depot or Lowes. Plumbing materials there are usually Taiwan, China, etc. and at least 25% of the time the threads leaked. I won't talk about valves or fittings that had pieces of steel embedded in the castings. An "inexpensive" steam fitting that fractures in a small boat underway can ruin your day.

[Lopez Mike]

I second Ron's advice. You will save money, time and aggravation by holding off until you have spent some time with other steam people.

The guy who half assembled Folly had zero contact with the local steam society. There was a shut off valve in the line to the safety valve! The rest of the valves were water valves from a box store with plastic handles which melted at the first trial steam up. I have an amazing tub of schedule something fittings that I replaced with sch. 80.

The right stuff lasts a long time. Junk is junk. One safety of the right size will be enough. Don't be alarmed if the safety groans and spits and isn't as sharp and quick to pop and seat as you would like at first. I've had two of them act this way when new but then settled right down after a bit of use.

Probably the only non-traditional bit on my power plant is the use of 29 degree hydraulic flare fittings as unions. Much better looking than ordinary pipe unions. More than strong enough and nicer to disassemble when needed. Also much less expensive when ordered on-line. I'll send you a link to a vendor if you wish.

I have yet to regret a few extra unions here and there. Disturbing NPT fittings is a pain. Goop all over me every time. How does it get in my hair?

Mike

[Mike Rometer]

Don't complain Mike - perhaps you're lucky it can get in your hair!

[Lopez Mike]

I wasn't talking about on my head!
m

[dwkoski]

Thanks for the help. Any advice on blowdown valves?

[Lopez Mike]

I use a quarter turn steam rated ball valve. I like the blowdown valve to have quick action. There are special valves made for this but I found them to be rather pricey. Mine is 1.5" on a VFT-30 boiler and I think that is over-sized though it works fine, especially when I want to blow down dry. Amazing commotion.