Pressure Test and Hydrotest Hand Pumps. Essential tools for safety and integrity in critical pressure systems.

So much large scale infrastructure for industrial processes relies upon vessels, pipework and key pressure components. If there is a failure under pressure, the operator has to face the consequences of safety for staff and the wider population, security, damage to the environment and ongoing business. A key process for operators is to pressure hydrotest complete systems to check for failure, leakage, permanent deformation or damage. Tests will be planned based on functional testing, proof testing or burst testing to meet various possible failure modes. Even low pressure testing is vital, as components can leak or fail at low rather than high pressures. Learn about functional, proof and burst testing in our video. To carry out these tests, specialised equipment like hydrotest hand pumps are used. You need to plan your testing, record the results and work both efficiently and safely. Sarum Hydraulics has manufactured its Micropac hydrotest pumps for 40 years and offers pumps to buy and web resources on how to test on its website.

What is a Hydrotest Hand Pump?

A pressure hydrotest hand pump is commonly seen as a portable and manually operated pump unit on a reservoir like our carry-around Micropac MP pumps. You might have a hand pump built into a fixed test unit bolted to a bench or wall or the test unit might be something like a skid or trolley using an air driven pump such as our Micropac PTR-M portable hydrotest pump. Another option is a pressure test pump like our neat Micropac Duo with a two wheel cart incorporating a rugged hand pump plus air driven pump in one very compact unit. All these pumps are designed to generate hydraulic pressure for carrying out pressure tests and hydrotests. These pumps are versatile, allowing technicians to apply pressure gradually and precisely to test and monitor the integrity of vessels, pipework and components in a system. These are specialist hand or air driven pumps and after 40 years, we are the experts. Micropac is our brand.

If the parts have been designed properly, why do I need to pressure test?

There could be an error or a failure mode overlooked during design. It happens. There could be something in a manufacturing or assembly process that compromises the strength. There could be an issue with materials. A period of use could compromise the strength of a component, for example through corrosion. Or a part could fail after many cycles, through fatigue failure. A pressure hydrotest using a Micropac pressure test pump or programmed pressure cycling test using a Micropac PTR-A pump is the ultimate test to provide assurance for Engineers. Testing is vital.

What are the key parts of a pressure test hydrotest pump?

A pressure test hand pump

Is the most common type of pump, although air driven pumps are also used. The pump must be compatible with the working fluid, so if the fluid is water, the hand pump will be suitable for this medium. Selecting the best choice of hand pump and seal material for your fluid is our speciality. Contact us.

The outlet non return valve

(“the outlet check valve”) is a key part and locks the pressure into the system being tested. On water, look for a poppet type valve with elastomeric sealing or at least a ball on a soft seat. A ball on a peened metallic seat as used in oil hydraulics doesn’t necessarily translate to very low leakage non return valves on thin fluids.

A hold release valve

Built into the pump will allow the pressure to be released after testing. This is invariably a needle valve.

A relief valve

Will limit the pressure that the pump can generate.

A pressure gauge or pressure indicator

Is vital. Users will require a calibrated gauge unless the device is simply for indication. A Borden tube gauge is commonly 63mm, 100mm or a 150mm test gauge. Or use an electronic pressure gauge, commonly with an output for data logging. A pressure transducer in the system will feed a data logger if a range of parameters are being recorded.

A reservoir

Needs to be adequate for the size of the system, compatible with the test fluid in respect of corrosion and safe to lift or move. A reservoir of over 10kg will commonly be offered with a two wheel trolley or cart for safe lifting and transport.

We’ve picked three key applications for pressure testing, each of which has a different focus and purpose.

Why would you pressure test complete systems as you might find in a petrochemical plant or even hydraulic machinery?

If you are supplying a system whether it is hydraulic equipment or a mega turnkey oil refinery, you can’t sign it off without checking whether it leaks. There will always be some sort of proof test at an elevated pressure and some functional test as described in a specification or drawing. Whether you have tens or thousands of parts all connected, there is the risk of a leaking or defective connection. That is reality. If you don’t test and it leaks or fails, you have safety implications and economic consequences. Plus, environmental problems even on the smallest systems. Plan your pressure hydrotest requirements then select the equipment that will do the job. Contact us.

Why is pressure Hydrostatic testing of Pressure Vessels such a big deal?

Hydrostatic pressure testing is a must for any pressure vessel. You are testing at an elevated pressure to provide a proof test and looking for leakage or permanent deformation. Why are pressure vessels such a big deal? Volumes of pressurised fluid are inherently high risk. People working at a location must be safe, the larger population must not be in danger, failure can be spectacular and of course the risk of environmental damage is always there. If we are talking of gas pressure vessels, the risk is considerably higher because gases are compressible and failure of a vessel is that much more dangerous as you are releasing a volume of expanding gas. Move to components like composite pressure vessels and control of the manufacturing process and the integrity of the design become issues to gain confidence on, based on testing the final product. As noted previously, pressurising a vessel for multiple cycles is a vital means of test particularly where a volume of flammable fluid is being stored for years as in a fuel tank or the manufacturing process is very demanding as for a composite pressure vessel.

Why would you pressure test after repair or maintenance work? Why might you pressure test a component every single day?

If you carried out repair or maintenance work on a system of any sort, you would test it at an elevated pressure to check that nothing was going to fail. Just running a system up and doing a functional test isn’t really adequate if for example, there is a risk that a single or double ferrule fitting has not been tightened enough and could blow out, or a hose hasn’t been tested and the swage could be poor. That is risk management.

Testing something every day or periodically does meet these requirements but has an extra dimension. Maybe more important is the comfort that a test might indicate if something is on the way to failing. If a result has changed, Engineers want to know why. For example, the Variable Guide Vane Actuator on a civilian airliner jet engine will be tested every single day to meet pressure test requirements. If there is a change, something isn’t right. That is good Engineering. There will be a reason.

How can Sarum Hydraulics help you with your pressure hydrotesting?

After over 40 years of manufacturing our Micropac pressure hydrotest equipment, we are the experts. We have our catalogue range and can always look at additional parts to meet your specific requirement. We run on multiple fluids from 0.5 bar to 1000 bar, but don’t get involved in high pressure gases. Contact us.

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