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News You Can Use: Issue 11

"Unparalleled Delivery Times on Custom and Standard Filtration Products”

Need to Replace a Suction Strainer and Can’t Find a Source?

You find you need to replace a suction strainer that may have been made by a company that no longer is in business or who doesn’t have any information on the part number or the company you are looking for? We may be the last call you will make. This means the next time we should be your first call. Look at the companies below, some of which you may never have heard of. OFCO may be able to help replace these parts.

How are Your Suppliers Delivering?

OFCO offers unparalleled delivery times. From flexibility and quality products to superior customer service, lean manufacturing processes, and more, Ohio Fabricators has earned the trust of countless OEMs and distributors over the past 75-plus years. Our goal is to deliver the highest quality products with zero defects. Whether they are custom made products or standard catalog filters and strainers, we deliver quickly. We stock most standard products for immediate shipment. Let us get you the products you need, with our unparalleled delivery times.

Hydraulic Principle Quiz

1. True or False? Fluids that flow with difficulty have a low viscosity. 

2. _________ is the study of liquids at rest and the forces exerted on them or by them.

3. _________ is the study of the forces exerted on a solid body by the motion or
pressure of the fluid.

4. Area is always expressed in ________ units.
B. Cubic
C. Either A or B
D. Neither A or B

See answers at the bottom

A Simplified Study in Filtration

Part 8 of 10

Sizing the Filter to the System

With filtration being as important as it is to the life of the entire system, proper sizing of the filter must be taken into consideration first and foremost. There are some basic questions that should be considered in order to determine the proper filter size. 

1. What is the flow rate (gallons per minute)?

2. What is the viscosity of the fluid?

3. What is the fluid?

4. What is the line size being used?

5. What is the type of filter needed?

6. What type of pump is in the system (vane, gear,
piston, etc)?

7. Will the system operate continuously, intermittently, or infrequently?

8. What temperature will the system be operating at (hot, warm, cool, very cold)?

9. Is the system indoors or outdoors?

10. What micron or mesh size is required?

Of course, the questions above are applicable if no information is known about the system you are trying to size. Most of the time you will have the information needed to make your job at sizing the system a lot easier. 

To make sure the filter you want to provide is used with the proper size pipe, please refer to the chart entitled, Oil Flow Capacity of Pipes. Of course to piece this altogether, you will find this chart in the next newsletter’s, Part 9. It will give you a basic understanding of pipe size vs. flow relationships. However, for a real fundamental lesson in pipe size/flow relationships you may recognize that pipe size should be selected on the basis of oil flow velocity.

In suction lines, the line size should be chosen which would keep oil velocity within the 2-4 feet per second range. In return lines, the oil velocity should be kept within the 10-15 feet per second range. Medium pressure lines carrying 500 to 2000 psi, flow should be kept to 15-20 feet per second. High pressure lines may be allowed to carry up to 30 feet per second in lines carrying 3000 to 5000 psi. 

On the “typical” side for matching pipe size with flow rate, follow the table below for easy and quick reference.

2 gpm: 1/4″ to 1/2″ NPT
3 gpm: 3/8″ to 3/4″ NPT
5 gpm: 3/4″ to 1 1/4″ NPT
10 gpm: 3/4″ to 1 1/4″ NPT
20 gpm: 1″ to 1 1/4″ NPT
30 gpm: 1 1/2″ to 2″ NPT
50 gpm: 1 1/2″ to 2″ NPT
75 gpm: 2 1/2″ to 3″ NPT
100 gpm: 2 1/2″ to 3″ NPT
200 gpm: 3″ to 4″ NPT
300 gpm: 3″ to 6″ NPT
400 gpm: 4″ to 6″ NPT
600 gpm: 4″ to 6″ NPT

These figures are very, very basic and can be used as a rough guide when making a determination in matching flow rate and pipe size. 

Next time, in addition to the chart Oil Flow Capacity of Pipes, we will touch on filter media, mostly wire cloth. Stay tuned.

Hydraulic Principle Quiz Answers1. False; 2. Hydrostatics; 3. Hydrodynamics; 4. A. Square