ASME requirements
I did a quick search on this site and others and I'm hopeful someone can chime in.
We take care of the heating and dhw systems at two decent sized local motels. Both sites utilize a bank of small cast iron hot water boilers (approximately 2 million input). The boilers are used to heat the building and provide dhw with a bank of 120 gallon indirect fired hot water tanks (four tanks at one site and six tanks at second site).
The original systems were installed in the 1980's and perform pretty well. However, some of the tanks have failed and a few of the boilers are leaking.
The state boiler inspector (pressure vessel) inspector was on site recently and informed the head of maintenance that the code requires these indirect tanks must be ASME rated. Is this a new code or is the inspector just enforcing a code that was over looked for many years? I am almost certain the boiler relief valves are set to 30psi at both sites. Domestic water pressure is approximately 50psi. There expansion tanks (for heating) are not ASME rated, nor have they ever been.
The site that the inspector mentioned the indirect tanks must be ASME rated happens to be on the second floor above the boiler room. I was told this room used to be motel room but was converted to a mechanical room by others many years ago.
Please share your thoughts. Thank you.
Comments
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did the inspector mention chapter and verse?
depends on what version of the recommendations your local authority follows
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Inspector did not mention the details. I suspect his written report will mention the code requirements. We are going to call him to get his interpretation of the code.
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This is my understanding but I have been out of the loop for a while.
my understanding with expansion tanks is they need an ASME rating if the relief valves on the system are rated over 30psi. 30psi reliefs and under do not require ASME expansion tanks.
As far as indirects go I thought the reason for the 119 gallon tanks was that 120 gallons or more require ASME and under 120 does not.
In both the above situations that is why you see on larger jobs you sometimes see multiple 119 gallon indirects and multiple non ASME expansion tanks.
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@EBEBRATT-Ed I agree with you one hundred percent on the ASME requirements for expansion tanks. I also agree with your premise regarding to the indirect tanks. Now that you mention it, I think every hot water tank (indirect, storage tank, steel tank with heat exchanger, or shell and tube were always ASME rated.
I will post after we speak to the inspector.
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btu and gallon capacity of the tanks, I believe
Boilers over 199k, tanks over 120 gallon or Btu input over 199,00
We run into this with hydraulic separators also.
As much as anything it is the inspector interpretations. So we make both ASME and non ASME product.
Bob "hot rod" Rohr
trainer for Caleffi NA
Living the hydronic dream0 -
Other than a label and a share of the cost of the testing added to the price, is the asme and non-asme product different?
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@mattmia2 I will let hot rod answer that one as he is connected to the manufacturing side.
With expansion tanks, buffer tanks, air separators, and hydraulic separators we see the ASME rated items are almost always thicker steel
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I'm curious how your inspector interprets this. I have sold a ton of commercial jobs with total boiler plant BTU over 199 and multiple indirect heaters and never had someone tell me the indirect heater needs to be a special ASME rated tank. I have probably 50 of the triangle tube smart 120s installed on a military base near us and each setup has about a million BTU/hr worth of boiler. The whole setup even appears on the schedule with engineer approvals and no ASME requirement, except the T&P relief valve of course.
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Boiler Inspectors in commercial applications seem to have become very focused on this stamp on equipment. I think that stamp has been required for over 100 years. Pressure vessels specifically being used/specโd for commercial/industrial use will have that stamp. Older quipment typically designed for residential use may not have that stamp.
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For ASME the welders need to be certified, the fabrication shop needs to be certified
All the material needs a paper trail all the way back to the mill that produced the steel, even nuts and bolts.
Occasional on site inspections that the manufacturer pays for.
Fees associated to be allowed to use the ASME label and shields
Donโt be fooled by products that indicates that they meet or exceeds ASME standards
That pretty much tells you it has not gone through the ASME listing protocol
Go to the ASME site to confirm the manufacturer does have ASME on the entire produce, report any cheaters
Bob "hot rod" Rohr
trainer for Caleffi NA
Living the hydronic dream
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I think most all boilers are ASME rated.
Where you run into issue is with boilers with a relief valve rated over 30psi and then the installer uses non ASME expansion tanks to save money.
I have gotten around this by installing a 30psi relief valve on the boiler and removing the 50 psi valve it came with as long as you don't need the higher pressure.
But you have to watch the boiler tapping size. Valves rated for the same BTU but for a higher pressure may have a smaller pipe size
I copied below something I found on the RAYPAK website
""Under ASME section IV part HLW rules, an ASME-compliant tank is required when the total system volume exceeds 120 gallons, or when the total heating capacity exceeds 200,000 BTUH.""
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What state are you in? In Massachusetts here I just took my annual training, and this is what I encountered for code changes. It appears in commercial installations, the total btu of all the tanks is being considered. The only exception is up to 4 tanks with UL-174 testing and a 10 year warranty. Who was the company that did the inspecting, Hartford, Federal, or another?
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We do large volume water heaters all the time and all are ASME rated. This is how the Mass plumbing code reads
(e) Large Volume Water Heaters and Storage Tanks.
1. Water heaters and storage tanks shall be stamped as ASME compliant when:
a. Installed in other than a private residence or a single condominium unit where the heater is serving only that unit and,
b. Have a storage capacity of over 120 gallons and/or a recovery equal to or greater than 200,000 B.T.U. and,
c. are direct or indirect fired. When determining the B.T.U. rating for an indirect fired water heater, the maximum output of the stored or transferred energy shall be utilized.
Examples:
a. An 80-gallon tank with a recovery rate 210,000 BTU must comply with ASME requirements.Two tanks installed, each with 100-gallon capacity with an indirect water heater with a recovery rate of 199,000 BTU feeding tanks shall meet ASME requirements.
Exception: Water heaters and storage tanks which meet the following requirements:
a. The tank conforms with the following UL-174 testing:
i. Section 33: Two (2) times the maximum working pressure or 300 PSIG maximum.
ii. Section 22: One hundred and fifty (150) PSIG and two hundred and ten (210) degree maximum.
b. The tank has a minimum of a ten (10) year warranty.
c. A maximum of four (4) tanks may be installed in tandem.
2. ASME Data Sheet.
a. Copies of an ASME data sheet attesting to the conformance with the requirements of the applicable section of the Code and signed by an authorized and qualified inspector shall be furnished to the owner and/or installing contractor.
b. A copy of the data shall be permanently displayed in a suitable mounting on a wall adjacent to the water heater.
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Unfired boilers are subject to ASME code. But I thought that industry used indirect power boilers to avoid regulatory hassles? B & M insurance inspector can require you to test anything with ASME stamp. Testing requires taking tank off line. How do you test compressed air tank?
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I don't know how they air test air tanks but boilers are a hydrotest
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hydrotest is 150% of rated pressure. But can you make your compressor do that? Do you borrow a more powerful compressor to blow into tank's outlet?
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Don't know about air tanks but testing any boiler or tank with air is dangerous. Air is compressed (obviously) and is like stored energy. So if you pressurize a boiler or tank etc it stores a large volume of energy and if it lets go you have an explosion (or could have).
They test boilers by filling with water and getting all the air out. Water is non compresable so it is not stored energy. If the boiler splits open under test the water runs out no stored energy because the water isn't compressed.
I guess they test air tanks the same way found this on line:
"Hydrostatic testing is a common method used to determine the safety and structural integrity of air tanks. The process involves filling the tank with water and then applying a controlled pressure to check for leaks and structural integrity. Here are the steps involved in hydrostatic testing an air tank:
- Fill the tank: Ensure the tank is completely filled with water, which should be 100% bubble-free.
- Apply pressure: Use a small pump to inject additional water after the tank has already been filled to raise the pressure to the necessary test pressure.
- Check for leaks: Look for any signs of leaks or deformation in the tank.
- Test stretch deformation: This test is difficult to perform at home and is typically done by professionals.
- Tag the tank: After the test, the tank should be tagged with the maximum allowed working pressure and the test pressure. It's important to note that hydrostatic testing is not always necessary, especially for older tanks. If the tank has been tested and is in good condition, it may not need a new test. However, for new or high-pressure tanks, hydrostatic testing is a critical step in ensuring safety and compliance with industry standards.4"
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Here are some experiences I've had with labeled stuff.
โขInspector noticed that water pressure in HHW boiler was 10 Psi higher than label after decades in service. Does thirty winters of service count as successful safety test? Alter label? Anonymously of course.
โขAn ancient ASME 50 psi boiler being used for steam heating at 0 psi. Safety official ordered a cold water test @ 50% over ASME rating. Popped at about 60 psi. At the time I was upset with official. But now I realize that following the law is the only safe thing to do legally. No matter how kooky it is technically.
This is why I advise people to use heating boilers for process steam if they can.
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Finally spoke to the NJ state inspector.
He is calling out the NJ version of National Standard Plumbing Code as to why they are forcing us to use ASME rated tanks on this job. Since the combined input of the multiple boilers is well above the threshold of 200,000 BTU (might have been 250,000) we must use ASME tanks. This will add a significant cost to the owner, but we have no choice in the matter. Thankfully, the owner understands the issue and trusts us to do the right thing.
Just learned non ASME tanks are in stock. ASME rated tanks are eight weeks outโฆ
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the person i saw do it used a preessure washer.
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Catch 22. Makes no sense. How can a non-fired domestic hot water heater fail catastrophically? I wonder if code writers studied ASME pressure vessel code. In Ontario one section is legislated while remainder of ASME code is ignored.
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Heating from an indirect source combined with no expansion room because of a waterlogged expansion tank or newly installed check valve somewhere and a failed relief valve or weakened tank would do it.
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Well maybe your stuck but I would check into it some more just for information. I know we have used multiple non ASME expansion tanks to avoid the ASME rule with no issues and the boiler was something like 800,000BTU.
Dont, know about indirects.
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I just found this in the MA. Plumbing Code, looks like the inspector is right. Just noticed this is the same thing @pedmec posted above.
it's common for most states to follow what ASME says.
"
(g) (h) ASME Requirements for Large Volume Water Heaters and Storage Tanks. 1. Water heaters shall be constructed to conform to the specific sections of the ASME Code when the heaters have the following features: a. Installed in other than a private residence. b. Having a storage capacity of over 120 gallons and/or a recovery equal to 200,000 B.T.U. c. Being unfired or heated by direct firing by means of oil, gas (natural, manufactured or bottled propane, etc.) or electric resistance elements. d. All safety controls required by ASME shall be supplied in strict compliance with ASME standards. e. f. Examples: i. An 80-gallon tank with a recovery rate 210,000 BTU must comply with ASME Standards. ii. Two tanks installed each with 100 gallon capacity with an indirect water heater with a recovery rate of 210,000 BTU feeding tanks shall meet ASME standards. The requirements of 248 CMR 10.14(10)(b)1. do not apply for water heaters installed in a single family dwelling only or a single Condominium unit having separate water heating source for the specific needs of that unit only
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Well, guess I am still learning. I have learned it is not worth fighting with the inspector (local or state) most of the time. I gather there are a few ASME rules that are not enforced, until they decide to. I suspect the rules will get tougher in an attempt to prevent accidents.
My father (deceased) on the other hand, looked at it like an opportunity. He was often technically correct, but it almost always cost him time and money to prove it.
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I never argue with inspectors unless I am positive I am 100% right.
I had a state boiler inspector who wanted us to look at a couple of steam boilers at the University of Mass. Larger boilers he wanted a low water cutoff (auto reset) and an additional manual reset control (LWCO) and a manual reset pressure control.
He was right about that of course but he didn't know what he was looking at because the boilers already had those controls.
There not always right but in you case it looks like the inspector is correct.
I had an electrical inspector who I got into it with once. MA electrical code is state wide so the local inspectors can't make up there own rules????? ๐๐๐ Of course some things are subject to their judgement.
In this case I recited the code to him and I was 100% right but he was one of these "not in my town I won't allow it"
I just said ok, we will have to go to Boston next month and go before the board. All of a sudden he decided to "let me get away with it" but "don't do it again"
Yeah, OK I promise!!!!!๐๐
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We went through this for years with Seattle and state of Washington as to whether indirects needed to be asme if they did not have capability of absorbing and transmitting 200,000 or more btus. The manufacturers took the state to court if I remember right and the code officials finally had to succumb to as long as mfr states in literature that the most they can absorb is 200mbh then they would be exempt no matter whether boiler was over 200 mbh. It was a back and forth for over 10 yrs as to whether allowed or not up until the matter was resolved and put in the code. Also tank has to be 119 gals or less water capacity.
The truth is that the heat exchanger does transmit more than 200 mbh when there is a high delta between tank temp and heat exchanger but I guess they ignored that. Just used the rated transmission of heat.
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the fictional 20 f delta tโฆ
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Seems to me that regulators sometimes lack seriousness or sense. Redundant pressure & temperature safety mechanisms are safer than grandiose QA measures. Virtually every failure for a hot water tank is a leak, not a burst.
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And the code makers would use what you said to justify there codes๐๐
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That's awesome. In my area the appeals board consists of members of our local building department, and their buddies lol. then if you appeal it to the state level, 2 of our local inspectors are on that board as well and the rest are their buddies. Kind of a racket here.
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MA is pretty tough and they don't play favorites as far as I am aware. The inspectors in the smaller towns are usually part time and as such don't want to "go to Boston"
Its usually not worth the fight for the size jobs I was involved with.
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ยปusually not worth the fight ยซ I feel likewise but OTH somebody has to speak up or our rulers will impose sillier & sillier requirements. I remember unfired high pressure steam generators chosen to avoid boiler rules. I think the company that made them was called Ameritherm?
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the maker of the temperature operated vent damper. i'd imagine it was a race between the damper and the spill switch once those became a thing
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