Dead Headed Piping – What is that?

We occasionally hear about a piping system that has been “Dead headed”, that is one of the downstream valves was closed against a running pump.

When this happens with a centrifugal pump, the pump “stalls” with no damage to the system.  However, when the pump happens to be a positive displacement type, the pump will continue to build pressure in the system. Without a relief valve between the pump and closed valve, something in the system will fail.  In the case where a Eaton strainer, Model 50, 5372 or 30 is installed between the pump and the closed valve, the cover O’ring generally fails after the system pressure has exceeded 450 psi.

Note: Eaton strainers are designed for 200 psi working pressure. They are individually tested to 300 psi. It is preferable there be no system failure, however, if something is going to fail due to excessive system pressure, the cover O’Ring failure may prevent catastrophic system damage and overall failure.

Remember proper system design includes installation of Eaton model 50, 72 and 30 strainers in systems that do not exceed the 200 psi* working pressure of the strainer.

For more information how Eaton filtration products can help you please contact you local Eaton sales representative today!


*Please note that Eaton’s 8″ Model 50 Strainer is rated at 150 psi operating pressure.

Quick Tip from AskFilterman: Strainers, Temperature and Pressure

Here is a quick tip from our very own Filterman:  Remember, there is a direct relation between temperature and presuure. As temperature goes up, the pressure the strainer can handle goes down! For more quick tips follow AskFilterman on Twitter today!

Making the Right Filter Choice

There’s no doubt that making the right filter choice for your plant can be a challenge. The right one can save you thousands in ROI, improve operational efficiencies, help protect the environment and decrease maintenance costs. The wrong choice can keep you from achieving optimum results. In addition to removing the undesirable material from a liquid stream, the filter you select also needs to meet other criteria. Here are a few points to help you to achieve your filtration goals…

        1) Installed costs must be weighed against operating costs.
        2) Waste disposal costs must be considered.
        3) Is continuous flow a requirement of the application, or can the filtration equipment be operated intermittently?
        4) Is working exposure to the process liquid during filter cleaning or replacement a problem?

The particles being removed from a liquid process stream are as widely variable as the types of filters designed to remove them.

Contaminants being removed in potable water treatment applications are often molecular in size. However, many other filtration applications are concerned with the removal of specific trace solids from a liquid process stream. Surface-type filters using fibrous cartridges of mesh screens made of woven wire or fabric are often used in these

Filtration Methods:
        When it comes to filtration methods, there are three basic filter types to consider in liquid processing:
             1) Self-Cleaning Filters
             2) Bag Filters
             3) Cartridge Filters

Each category has advantages and disadvantages when compared with the others. And, each one addresses filtration challenges for different applications.
Self-Cleaning filters are typically most appropriate for applications where:
        · Flow rates are high
        · Filter media replacement costs are high, or
        · Exposure of the process liquid to workers or the environment is undesirable.
        · They can be used to remove suspended solids of approximately one micron and larger from all types of liquid process streams.

Bag and Cartridge filters can both remove suspended solids for applications with lower flow rates, where:
        · Exposure to the process liquid is not a problem
        · Lower volumes of solids must be removed.
        · Bag and Cartridge filters are roughly equivalent in price, although self-cleaning systems tend to cost more initially.

        · Users should also consider the total operating costs of the filtration system, not merely the initial purchase price.

Overall, media replacement, disposal costs, labor costs, and downtime should all be included when evaluating filtration systems.