York Screw Chiller YCIV0357VA46

Refrigerant charge removed and all known leaks repaired?

System charged with a small amount of refrigerant mixed with dry nitrogen?

Electronic leak detector used to detect any small leaks?

Rated pressure of the unit refrigerant pressure relief valves not exceeded?

Conducting the gas pressure hold test

High-quality, high-resolution analog pressure gauge installed on one of the service valves?

All the system valves including manual valves and EEVs are 100% open?

All valves to the atmosphere are closed with flare caps in place, if applicable?

Install a high-quality, high-resolution analog pressure gauge on one of the service valves

All system valves including manual valves and EEVs are 100% open

All valves to the atmosphere are closed with flare caps in place

Unit is at the initial evacuation level of 5 mmHg

Charge with a vapor only for a 10% trace gas, R-134a based on nameplate, into the chiller until the system pressure reaches 10 psig (69 kPa)

Connect hoses to the high and low side of the system and add dry nitrogen into the chiller until the pressure reaches 100 psig (690 kPa)

Concentration of trace gas has reached all parts of the system

Any vented gas has been adequately vented from the chiller area

Test around each joint and factory weld

Warning: This procedure requires trained personnel with PPE!

Enter the amount of chiller refrigerant charge

Reference the unit Sales Order screen on the chiller control panel to determine the required charge

Enter the evaporator approach (STD)

If design values are not included, they can be provided upon request from the chiller sales engineer from the chiller rating program

Enter the Evaporator Saturation Temperature (EST)

Enter the Leaving evaporator liquid temperature (LCHLT)

Connect a high-capacity vacuum pump with indicator to the charging valves as shown in Figure 147 on page 306 and Figure 148 on page 306

Ensure all the system valves including manual valves and EEVs are 100% open

Ensure that all valves to the atmosphere are closed with flare caps in place, if applicable

Operate the vacuum pump until a pressure of 5,000 μm is reached

To start the 8-hour vacuum hold test, close the system charging valve connection to the vacuum pump

Hold the vacuum obtained in Step 4 in the system for 8 hours

Check for pressure change with the chiller at the same temperature

Warning: This procedure should only be performed by a qualified technician.

Has the system been carefully pressure tested and evacuated at the factory?

Enter the leak rate of the system (acceptable limit is 0.1 oz/year at DWP)

Are all joints tight and leak-free?

If any leaks are indicated, they must be repaired immediately.

Have all face seal nuts and flange bolts been correctly torqued?

For any major repair, the refrigerant charge must be removed and the system leak checked using reliable methods like a pressure test.