Positive Displacement Pumps

An experienced team you can trust.

What is a positive displacement pump?

A positive displacement (PD) pump moves liquids and materials by repeatedly trapping a fixed volume and displacing it into a discharge pipe and through the rest of a system. They are often used to pump viscous materials and operate through a cyclical pumping motion that’s driven by pistons, gears or screws.

While there are many types of PD pump designs, the two most common are rotary positive displacement and reciprocating positive displacement pumps:

Rotary pumps: These pumps utilise a rotating motion to vacuum up and capture fluid and may be used to transfer highly viscous materials such as sludge and dirt.

Reciprocating pumps: This type of pump uses one or more oscillating pistons or plungers, and valves ensure that liquid moves in the right direction. They are typically used in solutions that require a low flow rate against high resistance and pump out heavy fluids like slurry.

Seals for High Positive Displacement Pumps

What PD pump seal solutions do we specialise in?

FTL has crafted in-depth solutions to address the issues faced by PD pump developers across three areas:

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Rotary Seals

Rotary seals are of vital importance to the design of rotary PD pumps because they keep fluids moving, while also preventing the ingress of contaminants such as water and mud. Without a strong rotary seal solution in place, PD pumps will suffer from frictional heat build-up, internal damage from the system being clogged up with vicious materials, operational issues and a stoppage of the pumping process. In turn, this will lead to a higher level of cost in maintaining and fixing the rotary pump.

Reciprocating seals

Reciprocating seals are a key design element in reciprocating PD pumps, restricting the flow of sticky materials so it moves in the right direction and can be used for high pressure applications such as in the oil and gas industry. A critical part of any reciprocating seal system is the amount of pressure it can withstand, and they are often called ‘self-acting’ seals. This is because the design allows maximum contact pressure between the seal and housing walls to prevent leakage. Without adequate reciprocating seals, a PD pump is vulnerable to breaking down under high pressure, faces damage from hazardous chemical materials and excessive leakage. This results in damage to the environment through the material spillage and more money being spent on repairing and maintaining the pump

Cartridge seals

Cartridge seals offer an alternative to more traditional PD pump seals. They are self-contained units consisting of a shaft sleeve, seal and gland plate and are designed to reduce the risks commonly associated with seal failure. These risks range from an ingress of contaminants into the pump, to leakage of harmful chemicals that are hazardous to the environment. There are also challenges of high friction and a lack of lubrication to deal with, which negatively impact the overall performance of a pump.

Why choose FTL for your positive displacement pump solutions?

For over 2 decades, FTL have been providing in-depth PD pump seal solutions across multiple sectors and here’s why we’ve become experts in our field:

PD pump specialists

25+ years of experience
Direct contact with pump sealing engineers
A focus on optimising the overall performance and efficiency of all seals

Bespoke design and technical support

Developing high-quality seals from scratch
In-depth, forward-thinking customer solutions
A track record for success across multiple industries, including oil and gas, steel and more

Seal testing and validation

Centre of excellence for dynamic seals
Thorough benchmark testing and ongoing analysis
Solutions that reduce risk

Comprehensive supply chain management

OEM branded packaging for aftersales market
Stock holding