Diaphragm Pumps are widely used in a lot of industries and can handle a wide range of fluids. These pumps are used to transmit the fluids with low, high, or medium viscosities & also those with huge solids content. These pumps can handle many hard chemicals like acids as they are designed with an extensive range of diaphragms as well as body materials.
A diaphragm pump is also called as a positive displacement pump or a membrane pump. This pump functions with using a blend of the reciprocating activity of a rubber.
Types of Diaphragm Pumps
The diaphragm pumps are categorized into four different types, such as:
Air-Operated Double Diaphragm Pumps
Air operated pumps are used in a variety of industries like petrochemical to beverage and food. These pumps are versatile and popular. These pumps have unique designs and are ideal for transferring viscous and highly abrasive products. It is a kind of positive displacement pump that works by using compressed air as its power source.
Reciprocating elastomeric diaphragms and check valves are used by these pumps to pump fluid. The chambers are emptied and filled by fluid drawn by a common outlet and released through a single outlet. These pumps have good suction lift and can handle slurries or sludges with a high amount of solid content.
There is certainly some pulsation or vibration of the flow in these pumps. However, this pulsating flow in the discharge piping can be decreased by using pulsation dampeners.
Small Motor Driven Pumps
These pumps typically create pressures to 60 PSI (Pounds per square inch) to 100 PSI and generally have 1/2″, 3/4″, or 3/8″ inlet and outlet ports. These tiny motor-driven pumps are available in two distinct styles.
The “Demand style” involves a built-in pressure to start and stop the pump at particular pressure settings automatically.
The second one is the “By-Pass” style diaphragm pump in which the pump runs regardless of the pressure in the system. However, it internally bypasses flow when the discharge faucet is closed. And, when it is closed for over a minute or more, overheating of the fluid can take place and damage the internals of the pump.
Mini Air-Operated Pumps
With testing support and the rigorous engineering, the design of a mini envelop pump is used in low volume fluid dispense accounts. These pumps handle standard liquid viscosities, and no pulp juice concentrate easily. These are built on genuine flojet design.
These positive displacement pumps present a hydraulically-balanced design and sealless pumping that enables the pump to provide low-maintenance, leak-free performance during the processing of difficult fluids over a cast range of flows and pressures.
Characteristics of Diaphragm Pump
Because of their operating principle, the flow of liquid occurs at irregular intervals due to alteration of discharge and suction, which is called pulsation. This makes these pumps primarily different from centrifugal pumps.
When the fluid enters the cylinder through the functioning of a check valve, it flows out from the upper side. Speaking of closed operation, the pressure in the cylinder can rise infinity. But, before it reaches infinity, the weak parts near the pump might burst.
Check valve sealing is crucial. Sealing is hampered when dirt penetrated around the check valve. This can lead to disabling the non-return function, which impairs pump performance in a way that it stops discharging. The same can happen when the valve seat is damaged. In this case, wetting the valve seat and check the valve with liquid enhances sealing while making discharge and suction possible.
Advantages of Diaphragm Pumps
- They have the ability to handle a wide variety of liquids of high solid content. They are self-priming and explosion-proof.
- They can run dry with constant pumping efficiency.
- Do not overheat, submersible, and portable.
- They are inexpensive and require less maintenance.
Diaphragm pumps normally work best for hard chemicals and dirt-free fluids within fewer pressure applications. These are an extremely efficient kind of pumps because they can handle fluids with low, medium, or high viscosities!