Performance Under Pressure: Piston Pumps In Fluid Applications


China piston pumps tell us that piston pumps have been […]

China piston pumps tell us that piston pumps have been used for decades to meet a variety of transfer, extrusion, coating and dispensing requirements in many industrial and commercial applications. The versatility of the piston pump makes it the main force in all aspects from pressure cleaning, sand blasting, bonding, chemical dosing, potting, painting, lubrication and pavement marking to sanitary distribution. Given this versatility, the fluid type and viscosity of the materials being transferred and the associated flow rates and output pressures of these materials must be considered to ensure that the correct pump is selected for the application.

Piston pumps are classified as reciprocating positive displacement pumps that use a piston or plunger to draw and move fluid through a sealed cylinder.

The fluid inlet of the piston pump is typically immersed directly into the fluid, and then when the plunger reciprocates, the fluid is drawn into the pump by a negative pressure. The combination of check valve timing and plunger movement allows fluid to be dispensed in the up and down stroke, with an output pressure of up to 15,000 (psi) per square inch and a flow rate of up to 60 gallons per minute (gpm).

As the viscosity of the fluid increases and it becomes more difficult to draw fluid into the pump, the driven plate can be connected as part of the piston pump assembly and the fluid can be driven into the pump by pneumatic or by gravity.

Piston pumps are driven by a variety of motors, including pneumatic, hydraulic and electric.

Air motors are the most common choice because of their reliability, ease of maintenance, good power density, unwanted stalling capability, motor damage and inherent safety in volatile environments.

Hydraulic pumps provide better power density and quieter operation than pneumatics. Hydraulic piston pumps tend to prioritize mobile applications where the vehicle's power take-off (PTO) can be used, or when cold conditions in which motor ice can cause challenges. Motor-driven piston pumps are energy efficient, but due to the low power density, electric pumps do not provide the pressures required for many industrial applications, limiting the use of lower viscosity fluids and applications primarily involving transfer or injection.

Application pump type
Multiple pump ends are available for piston pumps to successfully handle a wide range of fluid characteristics. These are called the lower end and they have two types of balls, four balls and chopping. Double and four ball piston pumps are designed for low to medium viscosity fluids and are commonly used in transfer, cleaning and coating applications. For extrusion applications involving high viscosity materials up to 1 million centipoise (CPS) or more, heavy duty chopping and double ball pump assemblies can be used.

Demanding extrusion tasks often require additional accessories, such as pneumatic head assemblies and follower plates, to provide additional force to move fluid into the pump, thermal blankets to reduce material viscosity or fluid regulators to ensure precise dispensing control .

Although there are metrics for the ability to cross, there are limits to each type of piston pump. It is recommended to consult the manufacturer or distributor when determining the size of a particular application or selecting a pump.

Handling viscous conditions
When using a piston pump to transport challenging media with shear sensitive ultraviolet (UV) inks or adhesives with suspended solids, special tube and plunger coatings and fill seal materials are used. These minimize shear and heat and are resistant to any wear that may occur. Stainless steel pumps combined with ceramic-coated cylinders and piston rods offer water-based and wear-resistant properties that increase durability and reduce wear when using harsh materials. All of these features combine to help prevent premature pump failure.

Understanding the ultimate goal of fluids and applications is critical to maintaining product integrity. Some fluids require shear control or heat assist to achieve a viscosity that can be easily transferred while minimizing the risk of irreversible fluid damage.

A wide range of shear sensitive materials, ranging from lotions, soaps to pastes, cornstarch, inks, certain adhesives and certain coatings to all products.

This material requires low internal velocity and gentle pumping to limit damage and maintain its performance during transfer applications. In the microelectronics industry, many sealing compounds include the addition of fillers to improve performance.

This results in a mixture of solid and viscous properties which may present challenges for effective management of the application without damaging the pump or material.

Piston bag
Thanks to so many variables, the application software package is pre-configured with the right motor, piston pump, mount, controls and accessories to give the operator maximum flexibility. For end users, the pre-assembled and validated application package eliminates the guesswork of choosing the right pump for the job.

Challenging adhesives, such as multi-component or glass-filled sealants, require stainless steel or carbon steel piston packaging options, coated tubes and plunger rods to solve applications that are difficult to squeeze and transfer. For new or unique applications, it is recommended to refer to the pump manufacturer's viscosity and chemical compatibility resources, or consult an expert to properly package the package.

What is internal counting
Piston pumps are designed and designed to affect their function and performance when in use.

With a simple motor design, universal valve block and pump connection, the piston pump operator can easily move between motor sizes, create new pump ratios, and even upgrade the system without having to purchase a new pump. Other features include:

Progressive exhaust motor design to minimize icing
Adjustable packing seal and optional component coating to increase pump life
Quick disassembly for easy maintenance
Thermal release kit to prevent overpressure
All of these features make the piston pump a versatile, widely used choice for precise fluid movement.