Part Number GA_SM 08/18 63
Section 8 Refrigeration
Service Procedures
• Lokring fittings should be used to seal refrigeration lines
on R-290 systems.
• Tool part numbers and quantities of Lokring parts
necessary to service R-290 systems are as follows:
Qty Part # Description Notes
1 L13003829 Hand tool with double
hinge handles
2 L20000200 Assembly Jaw-Hand Tool
MB8
1 L14000878 Lok Prep 15ml Good for 1 yr.
12 L13000766 Brass end caps .25 Use 2 per cap
Phone numbers to order parts: PA. 800-304-0153 and FL.
877-861-0955
To purchase from other vendors reference # WX5X1 for
Lokring tool.
Review
• It’s advisable to use portable gas detectors when
working on R-290 units
• Before soldering on a R-290 system technicians should
evacuated and purged with nitrogen twice
• Maximum allowable non-condensable in a R-290 system
is 1%
• Evacuate the unit to a minimum of 500 microns before
charging
• Bubble leak test or gas detection leak testing are the
two preferred methods
• R-290 should be charged in the liquid state
• R-290 charges are typically 40% to 50% that of
fluorocarbon refrigerants
• R-290 operating pressures compare to that of R-22
• Be sure to ground the unit before servicing refrigeration
system
• Operate the condensing unit for a minimum of 5
minutes before evacuating to allow oil and refrigerant
to separate
• Propane detectors should always be used when
servicing R-290 equipment
• Reclaim and purge system twice before servicing unit
• Always cut components and fittings out of system –
never use a torch to remove components
• Never leave any type of access fittings on R-290 system
– always permanently seal the system