Do you know how to find the right diaphragm pumps for your company?
Don’t waste money buying the wrong pumps, only to have to replace them later on. A little bit of knowledge goes a long way toward choosing the best diaphragm pumps for the job.
If you don’t know what to look for, this guide will help you get started. Read on to learn the top tips for getting the diaphragm pumps you need.
Why Use Diaphragm Pumps?
When you need to move high volumes at a low pressure, a diaphragm pump is the way to go.
One of the main reason diaphragm pumps have become popular is that they don’t need oil to run. These pumps are often powered by electricity or compressed air, rather than oil. This means that they eliminate the air contamination associated with oil vapor.
Diaphragm pumps are a type of positive-displacement pump. Pressure is used to operate the valves or flappers, opening and closing them to provide a pumping action.
These pumps don’t wear out fast, thanks to their rubber diaphragms, rather than a piston-and-cylinder system.
How Diaphragm Pumps Work
Let’s take a quick look at the way these pumps do their job.
In the downstroke portion of the pumping action, the rubber diaphragm gets pulled down, and the volume inside the head of the pump increases.
Because of the volume expansion, the pressure in the pump head drops below the pressure of the inlet and exhaust.
The inlet’s higher pressure makes the inlet valve open up, while the exhaust’s higher pressure keeps the outlet valve shut.
Gas is pushed from the inlet into the pump head, through the valve.
During the upstroke motion, the diaphragm gets pushed upward, so the volume in the pump head decreases.
The pump head’s pressure then becomes higher than the pressure at the inlet and exhaust. This pressure keeps the inlet valve shut while allowing the exhaust valve to open. The high pressure moves gas out the exhaust valve.
Although this is a simplified look at how these pumps work, it will give you an idea of what you’re buying.
They’re a great choice for many different applications, but you’ll want to be sure you get the right ones for the job. How can you make the best choice? Here are a few things to keep in mind.
The first factor you should consider is the volume of material you’ll need to move.
There are pumps that can move about a gallon of material per minute – and then there are pumps that can move hundreds of gallons in a minute. It all depends on the size of the pump, and how fast it works.
The volume affects the pumping speed. The amount of space in the pump head affects how fast material can be pumped through, so you’ll need to get a bigger pump if you want it to move more material, or to move material faster.
You’ll want to choose a pump that runs at about half of its maximum capacity during ordinary use. This way, the pump will last a long time with minimal maintenance. If your pump is always running at close to 100 percent capacity, you’ll need to buy a replacement sooner.
You can easily find out the capacity of a pump before you buy – just check the product pages for more information.
You should also think about the type of drive behind the diaphragm.
The diaphragm needs to move back and forth in order to move material. What is powering this part? There are a few different options, including air drive and electric drive pumps.
The drive can affect where you can use the pump, and how safely you can operate it. For example, if you choose electric drive pumps, they’ll work anywhere electricity is available. However, in areas where a flammable material is nearby, they aren’t a safe choice.
Meanwhile, an air-driven pump can be used anywhere, as long as compressed air is available. You can use air-driven pumps around flammable and toxic materials without concern because the air can’t ignite anything.
You’ll also want to think about the material the pump is made out of.
There are usually a couple different materials in a diaphragm pump: one used to make the ball and seat, and one to make the body of the pump.
For example, you may see ball and seats made of stainless steel, or PTFE for the diaphragm.
The material you should choose depends on your needs. Stainless steel costs more but resists wear for longer. PTFE materials cost less but don’t stand up as well to abrasion. Stainless steel is also a good choice if you need a heat-resistant pump.
All diaphragm pumps have a performance curve, which can give you a lot of helpful information.
For example, the performance curve of an air-driven pump will tell you the volume of air that the pump needs at multiple levels of operation. It will also show you how much material can be moved at each operating level, and how far it can be taken.
You’ll need to pay particular attention to the amount of air that you’ll need to provide for the pump to move as much material as you need it to.
Keep in mind that you’ll be aiming to operate the pump at about 50 percent capacity, most of the time. The curve will show you higher operating rates, but you don’t want to always operate your pump at its highest rate.
Ready to Buy Diaphragm Pumps?
With these factors in mind, you’ll easily be able to select the right pumps for any application.
Diaphragm pumps are a great way to get the job done without contributing to pollution. And when you choose the best pumps for the job, you won’t need to worry as much about maintenance or replacements.
Thinking of investing in new pumps? Make sure to check out this guide for more information.