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Phil, Mechanical Engineer
Category: HVAC
Satisfied Customers: 6022
Experience:  Retired HVAC/ Electrical & Boiler contractor. Industrial
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Please I need the information about McQuay model PEH087 year

Customer Question

Please I need the information about McQuay model PEH087 year 1995 with 134A refrigerant and 500 tons refrigeration capacity system
1. safety valve set point in psi?
2. safety valve capacity?
3. MAWP of equipment?
4. operating pressure?
5. tons of refrigerant capacity?
Submitted: 1 year ago.
Category: HVAC
Expert:  Phil replied 1 year ago.

That data is best taken directly from the UNIT... the pressure vessels will have their certification plates welded to them those include the MAWP... the safety valve will have a tag on it with its capacity rating as well, or at least a model number on the valve we can look up.... it should be in this parts manual however... still the existing valve should be inspected for that information.

operating capacity varies with inlet and out let temperature of the condenser and chiller water... it will be a bit un 500 tons. as 12,000 btu/hr per ton.

Operating pressures vary slightly as well... in the 38-46 psig range for the chiller barrel, and 100 to 130 psig range for the condenser, depending on how clean the condenser and cooling tower is, and how it those are sized relative to the compressor, and the humidity as varies throughout the day.

This is a start, if you can tell me why you need this data, very specifically, I can be a lot more helpful.

Customer: replied 1 year ago.
I support to write New Jersey Blue Seal exams and on the application forms, these questions are asked.
Customer: replied 1 year ago.
please where will be the safety valve located on the chiller? is it the evaporator outlet or where?
Expert:  Phil replied 1 year ago.

the safety valve is either welded to the barrel of each heat exchanger and seen poking though the insulation...or is welded into the large suction and discharge pipes that connect directly to the compressor...

The question is clearly politically motivated as searching those details can take days, and of the thousands of chillers on the market, less than 1% are that model.. the idea is to feed the answers to the union home boys so that others can be screened out for not knowing those answers.

A few days google searching will locate most of that for you...still the answers you give may very well not match the ones listed the person designed this bear trap into the test since the test does not include the needed chiller water and condenser water temperatures etc.... clear indication that it is an entirely bogus question.... sort of like asking how many hairs are on the ass of an 800 lb guerilla... I am sure we could figure it out, or go to the zoo, but it is hardly a test of competence.

Sorry, I can't spend the time, I will opt out.

Customer: replied 1 year ago.
thank you very much