LT-S-L Technical manual
★
Note
：
External suction filter should be used for cryogenic refrigeration systems
。
5.1.2
Economizer Piping Layout
1
）
Economizer pipe dimension
A shut-off valve of the economizer is the standard accessory. It's recommended
to design the dimension of the pipes according to Hanbell suggested valve (Refer to
10.2.2 ).
2
）
Economizer check valve
When the operating conditions are unstable or when the economizer loop is
closed, a part of oil and refrigerant will flow back to the economizer pipe. In order to
prevent this phenomenon, this type of compressor is equipped with economic check
valve as standard.
3
）
Economizer intake filter
There is a built-in intake filter in the compressor, which is mainly used for
catching the impurities from the economizer and its pipes during the initial operation
to avoid serious damage to the compressor. This filter is not suitable for regular
cleaning and replacement of filter elements. If the system does have such
requirements, an external filter should be equipped on the economizer pipeline.
5.1.3
Minimum pressure valve
The oil pressure differential of the compressor between high pressure and
medium pressure shall be able to reach 2.5 bar in 30 seconds after start up to ensure
the lubricant can go into the compressor on time.
If the compressor fails to establish the pressure differential, it will cause
insufficient oil supply, leading to compressor shut down even damaging the
compressor.
Therefore, we provide a minimum pressure valve for LT series compressor so as
to achieve the pressure differential between high pressure and middle pressure quickly.
The minimum pressure valve should be mounted after the external oil filter, and
connected to the compressor medium pressure test point.
The location and installation of the minimum pressure valve is shown as below
picture.
