Goodmorning,

Is possible to carry out the hydrotest of exchanger not assembled?
In particular, first test is tube side with test ring, service gasket and tube bundle outside the shell;
second test is shell side with test ring, service gasket and tube bundle inside the shell, but without channel assembled.
The test pressure of the tube side exceed the test pressure of the shell by more than 10kg/cm2.
Please suggest me the better procedure for carry out the pressure test of HE.

Thanks & Regards

Please clarify the following
1. I assume that your exchanger is having U tube bundle
2. Channel head cover bolted with blind (or) welded with dish head.
3. Number of Channel head one (or) two -- front & rear

Goodmorning,

1. Yes the exchanger is with U tube bundle
2. Is welded with dish head
3.One Channel head

Thanks & Regards

Your sequence is correct but additional tube side hydro test shall be carried out to ensure leak tightness of gasket matting face of channel head with tube sheet gasket face and leak tightness of gasket matting face of shell with tube sheet gasket face.

1. Tube side Hydrotest : Channel head shall be bolted with tube sheet using the test ring & service gasket.CompleteTube bundle exposed without shell. In this test you can verify tubes integrety,Channel head welds integrety & leak tightness of gasket matting face of channel head with tube sheet gasket face.

2. Shell side Hydro test : Complete tube bundle shall be inserted to the Shell bolted with test ring and service gasket wthout channel head. In this test you can verify Tube to tube sheet joint leak tightness (if only expanded) (or) tube to tube sheet weld integrety (if welded),shell welds integrety & leak tightness of gasket matting face of shell flange with tube sheet gasket face.

3. Tube side Hydrotest : Channel head shall be bolted with shell & service gasket shall be placed in between channel head flange and tube sheet.(CompleteTube bundle inside the shell). In this test you can verify leak tightness of gasket matting face of channel head with tube sheet gasket face and leak tightness of gasket matting face of shell with tube sheet gasket face.

I hope the matter is clarified.

Many Thanks,

Kind Regards

In my opinion, the last test look redundant because if you use service gaskets in the first two tests, the matting faces of flanges are already checked (channel/ts in 1st, shell/ts in 2nd).

waiting for comments

Best regards

Hi,

The pressure test in which the item is not tested as a whole does not meet the code.

For clarification the following interpretations:

Interpretation: VIII-1-89-281
Subject: Section VIII, Division 1 (1989 Edition, 1989 Addenda), Hydrostatic Test of Completed Vessel
Date Issued: March 4, 1991
File: BC90-787
Question (1): A vessel is to be fabricated for non lethal service and is comprised of two shell courses joined by a bolted flanged connection. May each shell course be hydrostatically tested separately and the completed vessel, when attached, be Code Symbol stamped as a single vessel?
Reply (1): No.

Interpretation: VIII-1-01-04
Subject: Section VIII, Division 1 (1998 Edition, 1999 Addenda); U-1(e)
Date Issued: September 28, 2000
File: BC00-500
Question (4): In the manufacture of multiple duplicate pressure vessels employing removable upper heads, is it permissible to separately pressure test the vessel body and the removable head in satisfying the requirements of UG-99 or UG-100?
Reply (4): No, both UG-99 and UG-100 require pressure testing of the completed vessel as a whole

_________________
Kind regards,
Juergen Fleischfresser

Mr Juergen Fleischfresser
Thanks for the interepretations.

Mr rinosa,

If you want deliver the exchanger as a "U" Part, two hydro test is sufficient. For "U" Stamp it requires final Hydro test.

Good morning,

In order to improve my knowledge, could you indicate part of ASME VIII Div1 in which is clearly indicated that is needed to perform hydrotest of fully assembled heat exchanger to obtain "U" Stamp of whole exchanger?

Thanks in advance

Please refer the section U-1, U stamp is a final certification of the completed equipment.Final test is mandatory to obtain the Ustamp for the whole equipment.

Taking into consideration the above U-Bundle Exchanger with same construction and with tube side pressure higher than shell side.

My Test Sequence will be as follows:-

Test 1:- Open Bundle Hydrotest with Channel shell bolted to tube sheet along with test ring and service Gasket in place (complete Tube bundle Exposed without shell). Here I will check the Integrity of the Tube side Weld, Leak tightness for Gasket of Channel shell Flange to tube sheet and Integrity of tube to tube sheet joint as well as of tubes from Back side since, open bundle Hydrotest.

Test 2:- I will remove the Test Ring and will Insert the bundle into the shell. Will Bolt the channel head with the shell flange with tube sheet in between and service Gaskets in place and will pressurize the shell side. In this Test, I will check the Integrity of the shell side weld and also the leak tightness for gasket of the Shell flange to Tubesheet.

Note:
In Test 1, I am meeting the TEMA Requirement of RCB-1.31 which states " the shell sdie and tube side are to be tested seperately in a manner that Leaks at the tube joint can be detected from at least one side. When the tube side design Pressure is the higher Pressure, the tube bundle shall be tested outside of the shell."

In Test 2, I m Meeting the ASME Sec VIII Div. 1 Requirement of U-1 which states " U stamp is a final certification of the complete Equipment. final test is mandatory to to obtain the U stamp of complete equipment."

I this way I am also in compliance with the code, also Testing Every thing Which is required to be tested and Eliminating one Hydrotest as mentioned in the previous cases.

Do let me know If my procedure is correct and in compliance with the code......
Your suggestion are always welcome......


Regards,
Zaheer A. Shaikh.