Title Air pressure decay test on Carrier, Themoking, Starcool, Dakin
Name Admin Date 2020-11-03
 Reefer Container Inside air pressure decay test procedure as per Carrier, Thermoking, Starcool & Daikin Standards:

Especially for Xtend-fresh cooling unit of the Carrier, reefer factory has to pay a close attention to apply the sealant at the edges of the corner covers and the tectrol- track, meanwhile, the carrier cooling unit's components have to be re-sealed carefully on air separator and Eva. covers & etc and the others are same namely as the Carrier cooling unit is being carried out.

A.  Careful sealant application:

1 Two sides and bottom: Apply two times sealant for both inside and outside of tracks

2 Top: Apply two times sealant on outside and one time on inside .

Standard on side:

Standard on bottom: 2 rows in the tectrol track.



   flat rivet heads must be countersunk and flushed.

Standard on top :


Inside (Because there no tunnel on top area ,so only one time sealant application)

Out side

  3) at both edges of the top corner covers.

 4) Sealing on the joint parts of the cooling units

  5) cooling unit checks:

  Cooling unit spare parts are to be checked:


  eg., input air leaked through the air separator


   The rubber gasket of the evaporator : location applied on Eva cover: no good

    : replaced by Carrier


Eva cover has to be repaired ( Rubber gasket at corners )



 B) cooling unit bolts application / re-checking:

  1) more lock-tite has been applied on the threads of the bolts correctly.


  2) Squeezing power of the bolts by use of torque wrench at 160 N•M or 120 lbf


    Provided 160 N•m current or 120 lbf required ∴ conversion from lbf to N•m= (X4.45 ÷ 3.2808)
    e.g., (
120 lbf x 4.45)÷3.2808=162.75 N•m  1N•m÷9.8=kgf•m
16.3 kgf•m=1,630 kgf•cm

   C ) to apply vinyl cover into tectrol track


D) Air-leakage test:
  1. Air leakage test is done one by one at yard, Inspector is to confirm the condition and notes the result is 1.5~1.9 m³/hr with acceptable condition within the Spec.: Q=2.0 M³/hr measured at 250±10Pa. For  detailed test result is attached for reference.

Note: 1 inchH²o = 25.4 mmH²O ∴ 0.0254 mH²O x 9.80665E3=249.08891 = 250 Pa



        around at 1.9 M³/hr.

    to perform soapy water test for the door gasket and cooling unit bolts, in the meantime,
       any leakage defect is to be repaired immediately on the spot.



    2. after having air-leakage test done first, then air pressure DECAY test is to be carried out by 1 per 25 units.

     test terms;
    Carrier / Star cool:
) The minimal box requirement ( inside air pressure ) is a pressure decay from 2 inches WG (50mm) to 1 inch WG (25mm)  for eight minutes (8) or more on a 40 foot container


    Amb. temp: 10~11°C during test

   ♣ Start timing with pressure 2 inches WG (50mm), the ambient temperature today was 10~11

pressure decay actually up-to 45 mm for 8 min. : very good

     provided that 8 minutes go by or more, and the pressure is above 1 inch WG (25mm),
        it is acceptable.
actual 45 mm reaching for 8 min.

    Daikin / Thermoking:
 To pull out the drain hose outlet, and fill the hose with water to prevent air out
      (The drain hose must be filled with water up to the trap.)


5)  To fill the air until the internal pressure of the container box reaches 490 Pa ( 2 in WG : 50 mm ) and maintain the pressure for 10 min. and the pressure keeping is above 245 pa (1 inch WG (25mm), it is acceptable.

♣Note: Unit Conversion: 1 mH²o (WG) = 9.80665E3 Pa 25 mmH²o(1 inch WG) e.g., 0.025 mH²o x 9.80665 x 1000 (E3)=245.16625 Pa



490 Pa ( 2 in WG)

We also to record the retention time of which the pressure form from 490Pa ( 2 in WG :50 mm)declines to 245 Pa ( 1 in WG:25 mm., the result is 22min 33 seconds actually. thus it is very much acceptable.


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