低温管道设计Low-temperature Piping Design

Only For Italy TP Co.

Jul.1990

Low-temperature Piping Design

CONTENTS

1. Scope of use

2. Pipeline Design precautions

2.1 Measures to prevent shrinkage

2.2 cold

2.3 Hanger and Support

2.4 Valves

2.5 Others　

1. Scope of use

This provision applies to low-temperature line (-100 ℃ ~ -164 ℃) in the design, 0 ℃ ~ -100 ℃low temperature pipelines can refer to this provision.

2. Pipeline Design precautions

2.1 Measures to prevent shrinkage

According to B operator round the valve will not be exposed to the outer

surface of the valve A cold layer of the principle of determining the

minimum block size l.

(1) should pay attention to the nature of the pipe

Typically used for low-temperature austenitic stainless steel pipes, and its linear expansion greater than carbon steel. Therefore, austenitic stainless steel of the displacement is very large. Since many thin wall stainless steel pipe, so the intensity is lower, so consider these tubes to support the setting.

(2) reduce the pipeline contraction force acting on the pipe system, several measures

(A) the pipe system using self-expanding.

(B) with the expansion loop.

(C) use of expansion joints.

(D) Note that the displacement

In taking measures to absorb the displacement before the pipeline should be calculated at each point and clear, to prevent stent and the beam is pulled down.

2.2 cold

Bail on the low-temperature fluids cold temperature protection and isolation from the external environment. If the cold layer of small defects such as cracks, cracks, etc., will be on the tube the fluid have a greater impact at low temperature. Such as improper cold, water vapor from the outside through the insulating layer will produce condensation, and then freeze. Ice is growing, will undermine the cold material, affect the cold effect. Must be considered from the material, the use of cold wet low permeability material, the outer surface should also be waterproof using another cold material.

(1) and different thermal insulation, flanges, valves and meters can not be exposed, but rather use the cold material wrap.

(2) compared with the thermal insulation, insulating layer under the following conditions will be very thick. Therefore, you should consider the following aspects:

(A) taking into account the displacement of the pipeline, the pipeline and other pipelines, equipment, adequate support should be reserved between the gap.

(B) with different insulation should be considered on the cold pipe flanges, valves thick.

(C) drain and air defense control the minimum size should be considered the installation of security after the cold manner determined.

(D) will increase the hole through the floor, should pay attention to the relationship between the pipeline and the beam.

(E) increase in the vertical tube on the device should be considered more dense areas of the installation space between the pipe rack.