Solenoidvalve

Understanding the nomenclature is crucial to understanding the various factors affecting pressure relief valves and the operations that they, in…

Pressure relief valve testing is critical to ensure the proper operation of these valves and the proper functioning of the…

Valves

To get the proper expansion tank volume we need to add together the draw down capacity requirement and the thermal expansion requirement to get an additional 18% total volume required for the expansion tank. Most coolant systems are designed to operate with about 13 qts in the system. If we use a 13 qt system as our model. We would use the calculations below:

Checkvalve

Inline safety relief valve testing is a high-tech alternative to the laborious, expensive process of sending out safety valves for…

But is there a actually difference between some of these commonly used terms, and if so, what does it mean for you? Here’s a quick breakdown of two popular terms: safety valve vs. relief valve.

As you already know, there are a multitude of pressure relief valves out there. In the industry, we tend to use terms like safety valve and relief valve interchangeably. And for the most part, this makes sense. Most pressure relief valves are designed to do the same thing — release pressure in a system.

Safetyvalve

Pressurevalve

Topics: Product Tech, Engine Cooling Technology, Tanks

Drawdown capacity is the amount of coolant that can be lost before air reaches the water pump and is introduced into the system. Air bubbles in the coolant system can cause inconsistent cooling and can also prevent the thermostat from opening if an air bubble gets trapped underneath it.

Now that we have a better understanding of the technical definitions of both terms, you might be wondering if it’s okay to use the terms interchangeably. In most cases, industry technicians will understand what you’re talking about no matter which term you’re using. However, they are different fittings that serve very different purposes, so you should use the correct term for each.

In a 13 qt System a 2.34 qt expansion tank would be required. In a situation where a large enough tank isn't available a recovery tank can be used in order to take up some of the expansion volume needed. A recovery tank will collect any coolant that is expelled from the pressure relief. In a set up with a recovery tank it is important to make sure that the coolant system is still full enough to allow for drawdown.   For more info on setting up your coolant tank system, see our "Setting up Your Cooling System" blog post.

Thermal expansion occurs as coolant accumulates heat from the engine.  The 6% of the expansion volume is calculated from the amount that the coolant level will rise at 212 degrees F. This takes into account the density change of the coolant itself and all the components that are in the coolant system. If the volume is calculated incorrectly and an inadequate expansion space is provided coolant will be discharged from the system at operating temperature.  To prevent the possibility of spilling coolant a catch tank or a recovery tank can be used.

pressurereliefvalve中文

The general purpose of both safety valves and relief valves are the same. Both are pressure relief valves, and they are designed to let off pressure in any situation where a system becomes overpressurized. That said, relief valves and safety valves do function slightly differently:

reliefvalve中文

If you’re working on testing both types of valves, it’s critical to understand the difference between these valves, just so you know your facility is adhering to the proper testing schedule.

While both terms refer to valves used to release pressure from a pressurized system, their technical definitions are different. The term relief valve refers to a valve within a pressurized system that is used to control pressure for the optimal functionality of the system. Relief valves are designed to help your facility avoid system failures, and protect equipment from overpressurized conditions. With a relief valve, the valve releases (relieves) excess pressure to ensure the system stays at the optimal pressure level.The term safety valve, on the other hand, refers to pressure valves that are designed to protect people, property, and processes. In other words, the term safety valve refers to a failsafe or last-resort valve that will release pressure from a system to prevent catastrophic damage to workers or to systems, usually in the event that all other relief valves have failed to adequately control pressure within a system.

If you would like to know about the features to consider when choosing a tank open up our Aluminum Tank Designer's Guide by clicking below.

Whether you’re working with safety valves or relief valves, they’re going to need testing. Minimize downtime this year with AccuTEST’s high-tech pressure relief valve testing system. Offering real-time results and remote support, our testing systems can be used inline to test any types of pressure relief valve. For more information about our system, or for a free live webinar demo of the AccuTEST system in action, contact us today.

While both safety valves and relief valves work to release excess pressure, the way they go about it is different.  Let’s look in the differences in greater detail.

Pressurerelief valve

The main job of an expansion tank has to do with, not surprisingly, expansion.  As a basic requirement, expansion tanks should allow enough space for coolant to expand at normal operating temperature and not be pushed out of the pressure relief fitting in the neck.

The general rule of thumb for proper capacity of expansion is 12% of total coolant volume for draw down and 6% of the total volume for thermal expansion.

We answer the common and not so common questions that come up in our daily work as a designer and manufacturer of engine oiling and cooling solutions.