Its all about your temperature and pressure relief valve discharge pipe

How to Test Temperature and Pressure Relief Valve | Repair & Replace

Temperature and pressure relief valve discharge pipes are used mostly as security tools for any type of water heating appliances or machines you might have, mostly found in our household water supply heaters.

Well, these temperature and pressure relief valves are made with the intention of releasing water in any situation whenever temperature or pressure goes over and above the secured levels.

If the temperature and pressure relief valve we depend so much fails.  Than water temperature will rise above boiling point because of being overheated. This possesses a threat of a minor explosion.

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So, in case if the tank bursts, the water Inside the tank will be opened straight away into thin air. This is a pretty dangerous scenario because this reaction will turn water into vapor quickly by multiplying its initial volume.

The actual risk of having an explosion in your house

When there’s a lot of heat along with water inside a tank, it creates pressure waiting to burst out. Due to this reaction, the water in our heater produces a reaction that has the power to move our tank rapidly. At this stage, our tank could even be sent straight into the sky without the use of fuel. I’m not kidding.

Now, this may sound like a pretty cool college experiment that’s done at a laboratory for some of you. But, this is a very harmful reaction that can cause serious damage to your house along with losses to your other appliances.

And I do not need to mention the amount of harm this reaction could do to a human being who has proper sensors.

Although these types of eruptions aren’t that common among households.
We are using more and more water heaters in modern homes these days. Due to that reason, there is a possibility that these types of accidents could happen more often.

Of course, we are very cautious when it comes to water heaters but, we need to understand that the carelessness of homeowners has caused serious damages to property as well as humans in the past.

Unfortunately, still those same old common mistakes are not that rare even in this modern era. But due to the enhancement of technology, manufacturers have found out many ways of making these types of accidents much lesser than what they used to in the past. And that’s good news for sure.

severe cases of negligence are the main reason for these types of safety hazards to occur usually. And these types of accidents are common in old apartments where there are old heating appliances with defective functionality that needs heavy repair.

Activating the temperature and pressure relief valve discharge pipe

When the pressure or temperature exceeds secure levels, the temperature and pressure valve will be activated. This happens as an automatic function whenever required.

And the discharge pipe is there for routing back the heated water from the temperature and pressure relief valve to somewhere that has the possibility to be discharged effectively.

Thus, this discharge pipe must be connected to the valve. This connection is what makes the discharge pipe’s job so effective when it comes to the overall performance of the water heater, as well as the tank.

One might wonder, what’s the most important thing that’s crucial for the discharge pipe? Well, it should be made with recommended material only.
Discharge pipes should be built with either stainless steel, galvanized steel, CPVC or copper in general. But it is also ok if it’s constructed with polyethylene.

But if the pipe is made of PVC or any other form of plastics. Which are not approved, then we cannot recommend it. Sure, the pipe will do its job for a short period of time even though the discharge pipe’s material is not approved.

But the main reason not to use unapproved plastics is that these types of cheap plastics melt much quicker when compared to any other material that’s meant for discharge pipes.

What are the other important things that are crucial for the discharge pipe?

Above we discussed the most important thing that affects the discharge pipe in terms of both effectiveness and smooth operation. But that does not conclude everything about the temperature and pressure relief valve discharge pipe.

There are some other things we cannot ignore. Because the discharge pipe is what makes all other tasks smoother and safer. Therefore, it’s crucial for the discharge pipe to have the following characteristics I’m about to lay out below.

And by the way, the following characteristics are present in most of the good discharge pipes out there. But you need to make sure that all the below requirements are met.

The discharge pipe should fit in: meaning it shouldn’t be tinier than the diameter of the valve.

The discharge pipe should be installed in such a way, that it drains out water smoothly with the flow of gravity. not against it. This will stop you from doing extra work when it comes to draining out.

Water should not remain inside for long periods. this will ensure a good drainage system. And besides, you don’t want to have water contamination that leaves the whole area unclean.

Discharge pipes have a high tendency for water contamination. So, it is important to keep this in mind and not let it happen in our homes.


We do have control over certain aspects of the discharge pipe, although we don’t realize it at first. So, when it comes to the temperature and pressure relief valve discharge pipe, it’s highly important to give attention to the construction of the discharge pipe in the first place.

Therefore, if the discharge pipe is not built with material that’s suitable or recommended, it is advisable that you get hold of a good plumber and reconstruct it according to the norms of plumbing professionals.

But still, there are other factors that we need to consider when talking about the discharge pipe. So, it is also important to give attention to the other factors that are crucial for the effectiveness of the discharge pipe.
Mainly because sometimes these are the factors that are being overlooked and left unnoticed.

Although a TPR valve might never become activated, it is an essential safety component on boilers and domestic water heaters. Guidelines concerning these valves and their discharge pipes reflect real hazards that every homeowner and home inspector should take seriously.

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