PVC pipe is made of PVC resin, a plastic known as polyvinyl chloride. This means that the material’s physical compositions are affected mainly by variations in temperature – expanding when temperature increases and contracting when temperature decreases, which is a natural phenomenon as with all other materials. This, therefore, indicates that in addition to temperature, the material’s stiffness and pressure-holding ability are also affected by temperature changes. High pressure plastic water pipes are good for the drainage system.
With this in mind, it may be essential to consider the different temperature effects on PVC pipes to better understand how it functions under the influence of either warm or cold applications. You can also use a PVC pipe for hot water.
Effect on PVC Pipe’s Dimensions Due to Temperature Change
Polyvinyl chloride (PVC) is a thermoplastic, so its physical properties change with changes in temperature. Dimensions, pressure capacity, and stiffness are all affected by temperature changes. The published dimensions and performance ratings for PVC pipe and conduit products are usually applicable only to 73°F. The following will help to explain how PVC pipe and conduit products are affected by operating temperatures other than 73°F. And a better understanding of the usage of PVC pipe for hot water.
Dimensions
Like all materials, PVC expands when the temperature rises and contracts when the temperature falls.
The coefficient of thermal expansion of PVC is: 3.0 x 10-5 in/in/°F
In general, PVC pipe and tube products have a very large length-to-diameter ratio, so length changes due to temperature changes are most pronounced. As a rule of thumb when designing PVC pipe and plumbing, consider that for every 10°F change in temperature, every 100 feet of pipe changes 3/8 inch in length, hence it’s considered a high pressure plastic water pipe.
Pressure Capacity
PVC pipe increases in pressure capacity as temperature decreases and decreases as temperature increases. PVC pipe pressure ratings are for an operating temperature of 73°F. To derate PVC pressure pipes for operating temperatures above 23°C, either the rating or the rating is multiplied by the derating factor.
Use published pressure ratings sparingly in applications below 73°F. The most endorsed working temperature for PVC strain pipe is 140°F.
Pipe Stiffness
PVC pipe and tubing harden when the temperature drops and becomes flexible when the temperature rises. As with dimensions and pressure capacity, published pipe stiffness values are for an operating temperature of 73°F only.
Use published pipe stiffness sparingly in applications below 73°F.
What is The Baseline or Upper Temperature For PVC Pipes?
The standard reference point for each published PVC dimension is typically 22°C. Low or low temperatures generally do not affect the strength of PVC pipes. Note, however, that as the tubing warms up, it can no longer accommodate pressurised fluids and at the same time becomes more flexible. In addition, the resistance of PVC pipes decreases with temperature, so special care and protection should be taken to avoid unwanted effects.
As for the upper-temperature limit, the specific limits may vary depending on the exact specifications of the PVC pipe. Nevertheless, the most recommended upper limit is 80°C. Exceeding this temperature may damage the PVC pipe and cause the structure to collapse. In all other cases, the recommended continuous operating temperature is 40°C. This refers to 40°C across the pipe wall and applies to a constant flow of fluid at the same level. Thus PVC pipe for hot water should be made taking into consideration these factors.
Due to the low thermal conductivity of PVC, intermittent flow can cause liquid temperatures to rise. In such situations, the amount and duration of the release primarily determine the maximum temperature. This should be evaluated first based on the average limit of 60°C across the thickness of the pipe. Also, emissions at high pressure plastic water pipes are limited to small amounts and often of short duration, resulting in satisfactory PVC pipes.
Commercial applications that typically require large discharges over long periods of time should first seek specific advice before selecting the PVC needed to ensure efficiency.
Effects of Temperature on PVC Pipes
It is a well-known fact that PVC pipes are affected by temperature. For this reason, there are noticeable differences in PVC pipes, especially in dimensions, length, etc., when exposed to temperature changes. It’s important to study the effects of temperature before making high pressure plastic water pipes.
Effect of Temperature on The Dimensions of PVC Pipes
Small changes in the dimensions of PVC pipe with temperature are most pronounced by its dimensions, especially the length of the pipe. This phenomenon also occurs with temperature increases and decreases from the baseline temperature.
Effect of Temperature on The Capacity of PVC Pipes
From a baseline of approximately 22°C, the compressive capacity of PVC Resin decreases with increasing temperature. It’s very essential to keep the following factors in mind while making PVC pipe for hot water. To see the reduced print capacity, you should follow these steps with these numbers:
For example, if the initial capacity of a PVC pipe is at least 400 PSI at 22°C, this means the pressure at 43°C is determined using the formula: 400 x 0.50 = 200. This gives a new pressure capacity of 200. PSI.
It is also important to note that the drop in temperature does not adversely affect the base pressure capacity of the pipe. Instead, if the temperature is below 22°C, we recommend that you refer to the published baseline pressure capacities to confirm.
Effect of Temperature on The Stiffness of PVC Pipe
In terms of pipe stiffness, PVC pipe becomes stiff and tough when the temperature drops and flexible when the temperature rises.High pressure plastic pipe is thus difficult to attain. For a proper PVC pipe for hot water , and also considering it’s made of PVC resin.
To reduce the declared stiffness of PVC pipe or tubing at operating temperatures above 22°C, follow these steps:
0.93 times at 32°C. The same applies to 32°C x 0.88, 43°C x 0.84, 48°C x 0.79, 54°C x 0.75, and 60°C x 0.70. For use below 22°C, it is recommended to refer to the published pipe stiffness as it tends to be. conservative. Additionally, the above numbers can be used to compensate for the modulus of the PVC pipe.
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