Problem of effective heating length & cumulative rise height
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Effective length of heat tracing: According to the SH 3040-2012 Standard for Design of Pipeline Insulation and Jacketing in Petrochemical Industries, the effective length of heat tracing refers to the actual length along which the heat tracing pipe covers the pipe that is being heated (including vertical pipes)… See page 8, section 6.3.1. The SH 3126 and HG 20514-2014 Standards for Design of Heat Tracing and Insulation for Instruments and Pipelines define it as the total length of the heat tracing pipe from the steam distributor to the return water distributor. ……See page 6 of SH, section 5.3.3; the three specifications impose roughly similar limits on the effective length of the heat tracing tubes. Isn’t there some contradiction here? Regarding the limit on the rise height of the heat tracing tube, the specifications require the following: SH 3126-2013 5.3.4 b) The cumulative height shall not exceed the difference between the steam inlet pressure and the drain valve outlet pressure (in Bars) ； SH 3040-2012 6.3.1 d) The accumulated height of 0.5MPaG steam shall not exceed 6m ； HG 20514-2014 7.2.2 For heat-traced pipelines, the cumulative elevation increase in meters should not exceed the steam inlet pressure (in Bar) ； There are more or less significant differences among these specifications. My current approach is to use the total length of the heat tracing pipe from the steam distributor to the return water distributor as the effective length ； The cumulative heating rise height shall not exceed 5 m, starting from the point where the heating tube makes contact with the object to be heated. What do you all think about standardizing these differences? The question is how to arrange the cumulative rise height of the heat tracing tube?
I’ll handle it myself; I hope some expert can give me some advice
This post should be posted in the process-related forum; it’s not professional for engineering technicians working on the instrumentation side to handle this task… However, if there are any contradictions between the various national standards related to instrumentation, and if the site permits it, then the minimum standard should be followed in order to meet all relevant standards and regulations. Usually, the site does not allow adherence to the minimum standard, so we generally opt for the maximum standard; as long as a solution meets the requirements of any one of the standards, it is considered acceptable. We are a fine chemical enterprise, and we primarily refer to chemical standards; petrochemical standards may not be applicable to us. Therefore, when multiple standards conflict with each other, we choose the chemical standards in such cases.
I’m not quite sure about this. By \"several standards\", it means that the maximum length of the heat tracing should not exceed the pressure inside the pipe; in other words, if you’re using steam with a pressure of 1 MPa (10 atmospheres), the length of the heat tracing cannot exceed 10 meters……
Then he meant that the strainer should be installed at a low position, not at a high one~ otherwise it might conflict with the first standard~?
Yes, it conflicts with the specifications regarding the rise height of the heat tracing tube
But generally, strainers are installed at low levels, so there’s no conflict with height, and there’s also no issue between the rise in height and pressure~ Should be fine, right?
What if the instrument being heated is also located at a low position? The layout of the heat tracing branch pipes also needs to take into account the environmental conditions on site
There’s no need for each branch pipe to run that far; the main pipe can be moved there instead~
It can certainly be handled from the supervisor’s position. The problem is the understanding of the standards~ There are basically conflicts among these standards