Brazing Procedures For Zr*Kre Compressors In Parallel Applications; Shut-Off Valves And Adaptors - Emerson Copeland Scroll ZR24KRE Application Manuallines

▪ Recommended brazing materials: any silfos material is recommended, preferably with a minimum
of 5% silver. However, 0% silver is acceptable.
▪ Be sure tube fitting inner diameter and tube outer diameter are clean prior to assembly.
▪ Using a double-tipped torch, apply heat in area 1.
▪ As the tube approaches brazing temperature, move the torch flame to area 2.
▪ Heat area 2 until braze temperature is attained, moving the torch up and down and rotating around
the tube as necessary to heat the tube evenly. Add braze material to the joint while moving the
torch around the joint to flow braze material around the circumference.
▪ After the braze material flows around the joint, move the torch to heat area 3. This will draw the
braze material down into the joint. The time spent heating area 3 should be minimal.
▪ As with any brazed joint, overheating may be detrimental to the final result.
NOTE: Since the discharge stub contains a check valve, care must be taken not to overheat
it to prevent brazing material from flowing into it.

3.3.2 Brazing procedures for ZR*KRE compressors in parallel applications

Only compressor models officially approved by Emerson in the qualified configuration may be used
for parallel applications. For ZR*KRE compressors in parallel applications with passive oil
management, additional precautions shall be taken before brazing the oil and gas equalization ports.
The sequence shall be as follows:
First, install the compressors on the base frame and tilt the assembly so that oil will not be lost when
opening the cap. The gas and oil equalization line assembly should be ready for brazing at this point.
For new compressors, release the protective gas charge: the rubber plug from the discharge port of
the compressor has to be removed first, then the rubber plugs from the oil port.
Most probably the oil port will be coated with some oil. It is mandatory to clean out the oil before
brazing. If the inner surface is contaminated with oil the brazing material will not adhere to the surface
and the joint will fail, generating leakage. The oil should be carefully wiped out with industrial
absorption paper. Industrial solvents on a clean cloth can be used too but only with great care. Note
that emery cloth will not remove the oil.
It is possible that the oil cannot be completely cleaned out. In this case additional measures should
be taken. For instance, if a connection is coated with flux then the residual oil will be removed when
brazing due to the applied heat.
If an active oil level control is to be used, eg, Alco Controls OM* Traxoil, please refer to the product
documentation when brazing the connection adaptor.

Shut-off valves and adaptors

3.4
CAUTION
Leaking system! System breakdown! It is strongly recommended to
periodically re-torque all pipe and fixing connections to the original setting after
the system has been put into operation.
Copeland Scroll ZR*KRE compressors are delivered with a discharge check valve fitted inside the
discharge port and stub tubes as standard.
Brazing connections can be converted to Rotalock by means of adaptors. Rotalock shut-off valves
are available for the suction as well as discharge sides.
Figure 8: Shut-off valves and connection adapters
Torque settings from system valves and adaptors with Rotalock connections might decrease
significantly after some time of operation. Recurring temperature changes, vibration and other
influencing parameter could lead to expansion and contraction of the metal material and a relaxation
of the gaskets. Periodically retorquing the Rotalock connections to the original settings is
recommended.
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