System Design Recommendations; Airtight Method - Danfoss Optyma OP-UPAC015COP04E Application Manuallines

Application Guidelines

5.1 Airtight Method

Do not pressurize to specified pressure all at once, but raise it gradually.
Stop the pressurizing at each step of 10 bar, 30 bar and 70 bar, and leave it alone to see if the pressure drops.
Raise then the pressure to the design pressure, and record the ambient temperature and the pressure.
Apply a foam liquid over the surface. If no foam generates, it passes the test. It passes the test also if the pressure does not drop after
leaving it alone for approx. a day under the specified pressure.
It is necessary to apply correction for ambient temperature variation.
Example for 1 K (Kelvin) Ambient Temperature difference:
T1=20°C
=293K; (20 +273K)
T2=21°C
= 294K; (21 +273K)
PT1=80,0 bar; PT2=?
PT2 = PT1*T2/T1
= 80,0bar*294K/293K
= 80,3bar
Therefore, 1K temperature difference can cause a 0.3 bar pressure difference.
Absolute pressure at measurement = Absolute pressure at pressuring x
Absolute pressure = Gauge pressure + 1.0133 (bar)
(Gauge pressure is the pressure indicated on the manifold.)
If the pressure drops, it leaks at some places. Find and repair the leak spots.
When it leaks, check welded section and screwed section using foaming liquid.
Work sequence
End of refrigerant piping
Fig. 18
Note
High, medium and low pressures of this unit are displayed at the 7-segment indicator on the control PCB. They are not displayed when the power
supply is turned off. In such occasion, check them by installing a gauge manifold at the service ports of high, medium and low pressure sides.
(For the location of service ports, see the following figure.)
When venting the gas, start from the low pressure side. (Take care not to make the low pressure side of compressor higher than the high pressure
side.)
© Danfoss | Climate Solutions | 2023.02

5. System design recommendations

N gas pressurizing Pressure drop check
2
Check/correction of leak
(273°C + Temperature at measurement)
___________________________________
( 273°C + Temperature at pressurizing)
Recommended bubble leak test liquid
Passed
Bubble leak test liquid
Gupoflex
AB408540130380en-000102
Maker
Yokogawa & Co., Ltd.
31