The Steamboating Forum

I have a thread currently running on propane burner pilot size, and this thread deals with the water gauge on the same boat.

The builder currently has a half-loop, oriented upwards, on the steam leg of the water gauge.
My experience is with locomotives and I have not seen such loops before.
The loop was added to introduce some flexibility in the mounting of the gauge.

Can a loop such as this possibly lead to erroneous gauge readings ?

John.

Picture? Don't know what you mean by oriented upwards.

It's not uncommon on smaller boilers to have that sort of piping in order to accommodate a sight glass that is longer than the distance between the sight glass bushings on the boiler back head.

It's bad practice to have the sight glass below the minimum water level so it's vertical location is effectively fixed. The "loop" is just there to connect the top end of the sight glass to the steam space as needed.


Hope that makes sense.

Ken

If the 'U' is inverted. i.e., from the way it looks on a page, I suspect it wouldn't be a problem. I've seen the steam line to a gauge on a locomotive run a hell of ways to a manifold somewhere up on top of the boiler. But if it's right side up, is there a chance of water collecting in the bottom of the curve and screwing up the operation of the gauge?

Worth thinking about. Probably not a problem but we've been fooled before.

Electro, I have both my reflex water gauges hooked up in exactly the manner you describe. I did this to have the top of the gauge at the top of the boiler to get the highest reading possible. My boiler is quite short with 14" long tubes. The bottom of the gauge is still about 6 inches above the lower tube sheet. I installed a dry pipe that is a circle of 3/4" thin wall stainless tube with 457 1/16" holes drilled in the side of the tube that is upward and about 1/8" below the upper tube sheet. Because of the short tubes I wanted to carry the water as high as possible and with this arrangement I am able to carry it about 2" below the tube sheet. I have had no issue with carryover, perhaps the small holes break up the water if it does slop over as the boat rolls. The U-tube only serves as an equalizer, there is of course no flow, mine are 3/8" o.d. copper tube connected with Swagelok fittings. I brazed a half Swagelok 1/8" tube union fitting to the loop on each water gauge to run the 1/8" o.d. copper line to the fore and aft steam gauges, it is a nice quiet place to tap them in, they do not jump when the safety valve lifts.
Happy steaming, best regards, Steamboat Mike

The steam (top) connection of the glass can have any curves it wishes so long as there's nowhere for water to collect

- Bart
.

Yes. What Bart said.
Best regards, Steamboat Mike

Apologies for the poor photos, the family camera died a couple of weeks ago, so I had to use my old Nokia 2600C.

The photos show the water gauge piping.
I think the current arrangement should be acceptable.
The steam loop does not allow water entrapment, the water loop is straight, and the cocks allow proper blow-down and free passage checks.

Thanks for inputs, the builder and I have learned a great deal.

I showed the thread to the builder and demonstrated the benefits of being a part of a wonderful group like this.
I think I convinced him to join, we shall see.
John.

Just adding to my previous that the duplex pressure gauge is fitted for test purposes only.
The following photo shows the gauges for the boat.
And, my fault, the boat is 18 ft, not the 22 ft previously stated - it 'looks' so big on the trailer.


John.