Boiler Testing

This forum is dedicated to the Live Steam Hobbyist Community.

Moderators: Harold_V, WJH, cbrew

User avatar
NP317
Posts: 2995
Joined: Tue Jun 24, 2014 2:57 pm
Location: Northern Oregon

Re: Boiler Testing

Post by NP317 » Wed Mar 10, 2021 11:24 am

Harold:
Thank you for establishing this separate thread.

Marty:
Thank you for adding pertinent facts. Your expertise is appreciated.
I will add that Oregon State has stopped managing Hobby Boilers, and traction engine boilers.

RussN

User avatar
Steamer Al
Posts: 45
Joined: Tue May 26, 2020 3:17 am
Location: Comox, BC

Re: Boiler Testing

Post by Steamer Al » Wed Mar 10, 2021 12:27 pm

Thats a breath of fresh air to see the government actually relaxing regulations.... not the case with my other hobbies.

I still have the annual test/inspection certificates from my grandfathers 1904 sawyer massey traction engine. Every year or so the inspector lowered the rated pressure. It was a lap seam boiler, which inspectors do not like. One year I beleive it failed the pressure test due to corrosion in the firebox. Thankfully grandpa had a certified welder working for him at the steam plant! It is interesting to see regulations potentially going away from annual hydro tests.

Alex

User avatar
NP317
Posts: 2995
Joined: Tue Jun 24, 2014 2:57 pm
Location: Northern Oregon

Re: Boiler Testing

Post by NP317 » Wed Mar 10, 2021 12:59 pm

Interesting about the traction engine. Lap seam boilers do make me nervous.

The local Museum I volunteer at has a 1910 Aultman Tylor traction engine that we have steamed, pre-Covid. We are almost done rebuilding the engine, and will steam it up again this Spring.
Oregon State says boiler testing is entirely up to us. However, we gladly pay for the State Inspector to witness an annual hydro and steam test. Due to the lower insurance costs to the Museum for a State Certified boiler, this State approval is a financial investment for us. We will continue doing this.

Always understand your regional regulations, and "do the numbers" when considering such issues.
RussN

Steve Goodbody
Posts: 197
Joined: Thu May 25, 2006 7:16 am

Re: Boiler Testing

Post by Steve Goodbody » Wed Mar 10, 2021 1:57 pm

Hi all,

From my experience, both UK and US, I think it's important to make clearly the point that "one size does not fit all" and it's perhaps over-simplistic to think otherwise.

As specific examples, the following questions, listed in no particular order of importance as they're all important, really do matter when determining a boiler's construction and testing requirements:

1. Where (geographically) do you intend to operate your boiler?
2. What is the internal volume of your boiler?
3. What is its intended operating pressure?
4. What materials and construction methods were used?
5. Will it be operated in public?
6. What does your liability insurance coverage underwriter require?

As an example, in Pennsylvania I believe I could operate my boiler at a well-known club's track, located on private (not public) grounds, provided I have a boiler certificate that meets the club's regulations and that the club permits me to do so. I assume the club's regulations were not inherently set by a governmental agency but, rather, are likely supported by decades of no-loss experience sufficient to satisfy the club's insurer, and the club, that the attendant risks are well and responsibly managed through the club's adoption of, and adherence to, the test.

Further, from what I can see, this club's regulations appear very similar to regulations which I have seen at other clubs and societies over the years, in both the UK and at various US clubs, namely an annual dry 150% hydro-test supplemented with a <=110% steam accumulation test to verify correct operation of the primary pressure-relief devices. In other words, the club has, wisely in my opinion, adopted a test protocol which can be demonstrated to have a good national and international record of supporting ongoing boiler-safety.

By adopting and mandating a widely-used test protocol, the club gains further potential advantage should it ever have to defend its practices. Put simply, the club can legitimately demonstrate that it follows reasonable and accepted practices and, should the unthinkable happen, this would seem to be a good point in its favor and a good foundation for any defense that may be needed.

Lastly, and despite all of the above, I cannot legally operate this same boiler in a public forum in Pennsylvania. In other words, although it's the same state, and it's the same boiler, the rules are different. While my boiler would be demonstrably safe to run at the club's non-public location, Pennsylvania requires that publicly-operated boilers are ASME-stamped and tested accordingly. Hence, while my boiler is CE-certified (analogous to the ASME in Europe) it is not an ASME-stamped boiler, and I cannot retroactively make it so, and no testing regime can overcome that barrier.

Best regards
Steve
Last edited by Steve Goodbody on Wed Mar 10, 2021 2:06 pm, edited 1 time in total.

User avatar
gwrdriver
Posts: 3224
Joined: Mon Jan 06, 2003 10:31 am
Location: Nashville Tennessee

Re: Boiler Testing

Post by gwrdriver » Wed Mar 10, 2021 2:04 pm

All perfectly logical, reasonable, factual, and well-put Steve.
GWRdriver
Nashville TN

User avatar
NP317
Posts: 2995
Joined: Tue Jun 24, 2014 2:57 pm
Location: Northern Oregon

Re: Boiler Testing

Post by NP317 » Wed Mar 10, 2021 3:37 pm

More information, just for education:

1. Washington State Miniature Hobby Boiler definition:
"Miniature Hobby Boilers subject to certification are defined as those that fall within the following dimensions, limitations, and criteria:
1) A maximum of 16 inches inside boiler shell diameter;
2) A maximum of 20 square feet of total heating surface; See note #1.
3) A maximum gross volume of (5) cubic feet; See note #2.
4) A maximum allowable working pressure for steel boilers of 150 PSIG

Note #1: Total heating surface is the sum of the area of all the firebox surface areas and the flue heating surface area.
Note #2: The total volume of the boiler outside envelope less the volume of the firebox.

2. Commercial Miniature Hobby Boiler Defined:
Commercial Miniature Hobby Boilers are defined as boilers meeting the requirements
listed under Section III-1 (Miniature Hobby Boilers Defined), and obtained from a
recognized manufacturer or business properly registered or licensed for sales in a state,
or states of the United States of America. Such commercial boilers may be sold either as an
individual miniature hobby boiler unit, or as a part of a finished product (i.e. locomotive,
boat, tractor, etc.)

Note: Commercially fabricated Miniature Hobby Boilers that have had any modifications
or alterations made to the pressure vessel envelope, subsequent to purchase, will be subjected to
the requirements of miniature hobby boilers in Section III-1 above."

RussN

User avatar
pat1027
Posts: 267
Joined: Sat Oct 09, 2004 3:45 pm
Location: Michigan

Re: Boiler Testing

Post by pat1027 » Wed Mar 10, 2021 7:02 pm

The commercial/industrial world is different from the model world. In the commercial/industrial realm my state requires a minimum safety factor of 4.5 for existing installations and 5 for new. A properly conducted hydro-test is not going to damage the boiler. The key there is properly conducted. Put Schmuckatelli in charge of the test and yes there is a risk. So with other methods offering less risk and the limited information provided by a hydro-static test, forego the hydro-static test and use other methods.

In the hobby world, while a hydro-test in itself will not guarantee the boiler is sound and safe, it is a tool in the tool box. My opinion there is no good reason not to do a hydro-test test. Couple it with good maintenance, cleaning, storage and an inexpensive bore scope.
Steve Goodbody wrote:
Wed Mar 10, 2021 1:57 pm
Further, from what I can see, this club's regulations appear very similar to regulations which I have seen at other clubs and societies over the years, in both the UK and at various US clubs, namely an annual dry 150% hydro-test supplemented with a <=110% steam accumulation test to verify correct operation of the primary pressure-relief devices. In other words, the club has, wisely in my opinion, adopted a test protocol which can be demonstrated to have a good national and international record of supporting ongoing boiler-safety.

By adopting and mandating a widely-used test protocol, the club gains further potential advantage should it ever have to defend its practices. Put simply, the club can legitimately demonstrate that it follows reasonable and accepted practices and, should the unthinkable happen, this would seem to be a good point in its favor and a good foundation for any defense that may be needed.
In Michigan model boilers had been exempt from rules and inspections. The state knew they existed and did not consider them to be a risk. In fact they still don't consider them to be a risk. The boiler division doesn't really even want to inspect us. But bureaucrats in a turf war forced our boiler division to implement inspections. The boiler professionals were satisfied enough with how the clubs handled inspections that they largely used club inspection practices as a model for the rules. The rules allow for clubs to perform their own inspections (though I think none do). There is value in what Steve says.

User avatar
Dick_Morris
Posts: 2419
Joined: Sat Jan 04, 2003 2:09 pm
Location: Anchorage, AK

Re: Boiler Testing

Post by Dick_Morris » Wed Mar 10, 2021 8:45 pm

This is the exemption in Alaska statutes:

(7) manually fired miniature boilers for model locomotive, boat, tractor, or stationary engines constructed or maintained as a hobby for exhibition use, having a volume less than five cubic feet and grate area less than two square feet and equipped with an American Society of Mechanical Engineers coded safety valve of adequate capacity and size, a water level indicator, and pressure gauge;

The smallest ASME safety valve is 1/2" pipe thread. I have one fitted to my CP-173, along with a smaller model safety valve. If I had my way, there would be an option for a smaller safety valve for smaller engines. The ASME valve is too large to be practical for anything smaller than a large sized 1/8 scale locomotive.

Alaska State miniature boiler definition:

(B) miniature boiler - a power boiler or high-temperature water boiler that does not exceed the following limits:
(i) 16 inches inside diameter of shell;
(ii) 20 square feet heating surface; this subparagraph is not applicable to electric boiler;
(iii) five cubic feet gross volume exclusive of casing and insulation; and
(iv) 100 psi maximum allowable working pressure;

If I had my way, the working pressure would be increased to between 125 to 150 PSI.

I can only think of six or seven steam locomotives in the state, all 7-1/2" gauge. I suspect no more than a couple of them have operated in at least five years.

It would be interesting to see what the laws and regulations are in other states, particularly any allow use of a miniature safety valve and maxiimum allowable working pressures higher than 100 PSI.

User avatar
Dick_Morris
Posts: 2419
Joined: Sat Jan 04, 2003 2:09 pm
Location: Anchorage, AK

Re: Boiler Testing

Post by Dick_Morris » Wed Mar 10, 2021 9:11 pm

On full-sized Alaska Railroad #557 we used an ultrasonic tester to inspect the thickness of the boiler. We made several thousand measurements. Depending on where they were done, measurements were on grids from 3" to 12" spacing. The measurements proved the shell to be essentially the same thickness as when it was built 70 years ago but also showed that there was considerable erosion in the water legs on the sides of the firebox. (Our $300,000 surprize.)

Use is simple. Each measurement requires that a small area be cleaned/polished, the surface is covered with a special gel, and a small probe applied. The thickness can be read within a couple of thousandths. I suspect these testers were extremely expensive when most of the hobby boiler testing plans were developed, but they can now be had for $100 to $125. Have any groups incorporated one into their boiler testing program?

User avatar
Bill Shields
Posts: 6502
Joined: Fri Dec 21, 2007 4:57 am
Location: Somewhere in the World
Contact:

Re: Boiler Testing

Post by Bill Shields » Wed Mar 10, 2021 9:30 pm

I believe that there is an ASME line about below 100 PSI

Regarding ultrasonic testing...many small boilers do not have the real estate between stays to use them

And with copper...not really needed since corrosion of sheets is rarely a problem
Too many things going on to bother listing them.

Glenn Brooks
Posts: 2420
Joined: Mon Nov 10, 2014 1:39 pm
Location: Woodinville, Washington

Re: Boiler Testing

Post by Glenn Brooks » Wed Mar 10, 2021 11:47 pm

I have also heard that the national code specifies 100 psi for hobby boilers. So maybe that is what perpetuates the 100 psi requirement. Of course, a state that adopts it’s own code, can increase boiler pressure to 150- as Washington has done, and If I remember correctly, also Hawaii. As to where 100 psi first came from, I have a 4-4-0 with a 14.5” boiler made in 1904. The safeties are set for 100 psi, which corresponds to the .250” thickness boiler shell material, apparently commonly used in the era.

Glenn
Moderator - Grand Scale Forum

Motive power : 1902 A.S.Campbell 4-4-0 American - 12 5/8" gauge, 1955 Ottaway 4-4-0 American 12" gauge

Ahaha, Retirement: the good life - drifting endlessly on a Sea of projects....

User avatar
Dick_Morris
Posts: 2419
Joined: Sat Jan 04, 2003 2:09 pm
Location: Anchorage, AK

Re: Boiler Testing

Post by Dick_Morris » Thu Mar 11, 2021 1:30 am

national code specifies 100 psi for hobby boilers.
ASME classifies them as "miniature boilers" with their own section of the boiler code, as opposed to power boilers which are those that exceed the definition for miniature boilers.

Post Reply