I will explain about the pipe shoe with insulation.
A shoe is a type of piping support that is also listed in the Plant Piping Pocket Book.
There are so many types of support that it can be difficult to know which one to use (or rather, they all seem to be the same).
There are several types of choux.
By reading this article, you will be able to learn about the differences between them and acquire the mindset to choose the most suitable one for your worksite.
Purpose of pipe shoe
The purpose of the shoe is to support the insulated piping.
When distinguishing between bare piping without insulation and piping with insulation, some considerations must be made when installing them on the same stand.
This is because for piping with insulation, you have to consider the thickness of the insulation.
Main types of pipe shoe
There are several types of shoe.
Let’s introduce three major types.
Direct welding is a method of directly welding the hissing height adjustment part and the piping.
The shoes and the plate itself are welded together, but the plate and the piping are not welded.
Like the plate, the clamp is not welded to the pipe, but it is designed to surround the outer circumference of the pipe and stop it.
Production cost
Direct welding is the cheapest manufacturing cost.
The cost of backing plates and clamps increases as the size of the parts increases.
However, when considering the overall plumbing work, it is at a negligible level.
Heat retention workability
Direct welding is the easiest way to install insulation.
Plates and clamps are more difficult to install as they increase the number of parts that impede heat retention.
This is also within the margin of error as long as it does not affect heat retention.
When it comes to deciding whether to use a backing board or a clamp, if you want to be more reliable, you’ll probably choose a clamp, but it’s not uncommon to choose a backing board for ease of construction.
corrosive
Direct welding is the most disadvantageous when it comes to corrosion.
Shoes are generally made of SS400.
Direct welding is fine for SGP piping, but there is a risk of contact corrosion between different metals when welding directly to SUS304 or other piping.
The backing plate and clamp type may collect liquid, which may cause corrosion.
The structure of the back plate is simpler than the clamp type, so it is less corrosive.
In recent years, there has been an increase in the number of cases in which corrosion prevention is being attempted with paint, tape, etc.
In either structure, the shoe rubs against the piping. Because it is a structure that collects rain while rubbing against each other, corrosion progresses much more quickly than on a typical exterior surface. Even if the piping can be replaced fairly easily, replacing the stand is very difficult, so it’s best to think about it from the perspective of protecting the stand.
Shoe dimensions
We will introduce the basic concept when designing shoe dimensions.
It is assumed to be a plate or clamp type.
Length and height are design elements.
length
The shoe length is calculated based on the amount of expansion and contraction of the piping.
The expansion and contraction of piping is the amount determined by the following:
Thermal expansion coefficient of piping × Temperature change of piping × Piping length
For long-distance piping on stands, expansion joints are used to absorb thermal stress, and the same idea applies to supports.
If the elbow or flange interferes with the chute when the pipe expands or contracts, it will be a problem.
Set the length to be large enough so that it will not be affected even if it expands or contracts.
If you use a direct welding type , be careful that if you weld it to the stand, it will become a fixed piping.
height
The shoe height should be at least the insulation thickness.
The insulation thickness varies depending on the operating temperature, so there may be differences in whether to use shoes of the same height or to set shoes of individual heights.
special shoe
If it is directly welded to the stand, it will become fixed piping.
When trying to deal with this problem, we will consider the following slide type.
The shoe is not welded to the stand.
The piping and shoe are welded together.
The shoe rests on a stand, but it moves forward, backward, left and right.
If you attach guides to the left and right here, you will have a sliding type that moves only in the front and back sides.
This method can also be used for piping that experiences severe thermal fluctuations.
reference
Piping designers should know about piping parts such as shoes, but mechanical and electrical engineers are surprisingly unaware of them.
Use the following books to systematically acquire basic knowledge about plumbing.
related article
related information
lastly
We thought about the types of shoe that can be used to support piping with insulation.
There are various types such as direct welding, plate type, and clamp type.
Even if there are difficulties in cost and workability, the clamp type is overall efficient.
Any method will increase corrosion, so take appropriate protection measures.
Please feel free to post any concerns, questions, or concerns you may have regarding the design, maintenance, and operation of chemical plants in the comments section. (The comment section is at the bottom of this article.)
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