Rotary Gear Pump

Rotary gear pump

External gear pumps is the most used & most reliable pump for the majority of the applications in positive displacement pumps. With a little modification, the external gear pump can be converted to external bearing or API pumps with casing in steel and mechanical seal versions. It is also the most widely used pump for lubricating applications. There are two types of external gear pumps the external – bearing type with internal bearing and bushes and the internal gear pump with external bearings.

Earlier most of the gear pumps were of spur gear design, however, the concept of spur gear changed in recent times due to larger size casings and cost inputs. Now, most of the pumps come with helical or herringbone designs for transfer & pressurizing applications.

For more viscous applications & to compete with costly screw pumps for high viscous applications double herringbone gear pump was developed.

The cost of this pump is one-third the cost of the screw pump.

The screw pump however has a longer life than the quad gear pump since the two screws don’t touch each other.

The lower NPSH constraints also make screw pumps an ideal choice for refineries & longer pipelines.

The cost saving of the gear pump cannot be matched by any other positive displacement versions.

Hydraulic Pump

Hydraulic pump is also a kind of positive displacement device.

The function of a hydraulic pump is a little different from normal transfer or pressurizing pumps.

The function is indirect. The hydraulic pump with its precision internals converts power energy into hydraulic power with its high liquid pressure creating characteristics.

Hydraulic pumps are also available in gear pump, vane pump, reciprocating pump, screw design.

Due to its high precision gears which are profile grinded is a better form of Positive Displacement pump. It has less slip as slip causes pressure formation to also slip.

Since the hydraulic pump is used for transmitting hydraulic oils of less Viscosity. Micron filters are required to sieve the oil before it enters the pump. While Positive Displacement pumps can handle impurities abrasive or corrosive mater. This is not at all possible in hydraulics.

These can operate in between 10 bars to 400 bars.

It is such an important device that if the loss in pressure results can cause total failure of the device it is used for.

Y Strainer

When determining which kind of strainer to use, it is vital to apprehend the particular functions and variations that make a strainer unique. Y strainers are no exception. While this strainer choice is extra bendy when in contrast with basket strainers, the strainers have a very confined installation. The kind strainer reason is a particular one and that is precisely what makes them best for the functions the place they can be used. This potential that perception the strainer’s reason and the functions that advantage from it are the great approaches to get the effects that you are searching for out of this strainer!

The Y Strainer Purpose

The y strainer motive is to eliminate undesirable particles from steam, gas, or liquid by the use of a straining aspect commonly made of wire mesh. Using this mechanical system in pipelines helps to defend the whole thing from pumps to steam traps. Y strainers are now and again designed with “blow-off valves” to make the cleansing method easier.

Perhaps the biggest gain that comes from the kind of strainer is its flexibility. It can be set up in a vertical or horizontal position, relying on the users’ preference. While this strainer kind is already a budget-friendly option, the measurement of y strainers can be decreased to keep even extra money. This additionally prevents the usage of extra materials. Y strainers can be made of a range of materials. The kind of fabric you pick out relies upon the enterprise and utility that is used. Any type of quit that you may want is on hand as well. From socket to flanged, there is a y strainer out there with the stop you need!

The approaches in which y strainers can be custom-made are reputedly infinite when in contrast with different sorts of strainers. However, the graph of a y strainer needs to be gorgeous for the software for this machine to be successful. In order to get the proper results, constantly be certain to recognize the utility you are working with earlier than shopping for a y strainer.

The industries where y strainers are best used are those that want regular safety from debris. The most universally common use for a y strainer is in steam applications. Due to its shape, a y strainer has no bother managing the excessive strain that steam functions endure.

Y strainers are regularly used in liquid applications. Sand and gravel are two very frequent kinds of particles that pose a massive hazard to liquid applications. When mixed with water managing applications, y strainers are a useful resource in the safety of tools that would be in any other case broken or clogged by way of a number of undesirable particles.

Natural gasoline and air functions additionally gain from being used with y strainers. Much like steam applications, herbal fuel and air environments have high-pressure levels. These purposes are additionally anticipated to put up with excessive temperatures, something that y strainers can easily endure.

Because of the range of industries and purposes the place a y strainer can be used, the substances and customization of these strainers should be carried out on a case-by-case basis. For example, carbon metal does now not do nicely in extraordinarily excessive temperatures or pressures, so it would be qualified to discover a y strainer made of chrome-moly metal for steam or herbal fuel applications. Keeping in idea specificities when it comes to functions and industries will assist make sure that you get the most from a y strainer.


Y type strainers trap impurities when installed in a system.

Cooling Coils

The cooling coil is the heart of most industrial cooling equipment, these coils can be of different shapes and sizes and determine the efficiency and effectiveness of industrial cooling systems. These coils can be of copper or stainless steel according to the specifications

industrial cooling & heat transfer coils

cooling coils are used to dissipate heat through finning, coil area increase, air blow, refrigeration.

The heat of refrigeration systems must be transferred through any of the above channels to increase & regenerate system performance.

Cooling coils are manufactured in different configurations through different materials which are good for heat transfer

Like copper, aluminum, brass, stainless steel.

Oil Cooler

Oil cooler

The oil cooler is an important but underrated device in the industry.

Oil, which runs the industry is one of the most expensive inputs to the industry.

The life of oil must be extended to save machinery & money.

When temp of oil goes up beyond limits it does not provide proper lubrication to the machines.

Once the oil is exposed to high temperatures it starts to lose its lubrication properties.

Cleaning of oil also extends the life of the oil.

To provide hardening, or annealing certain metals are heated and cooled in oil.

Cooling of oil is not an easy proposition.

To cool oil the viscosity should be less than 100 CST.

High viscous oils above viscosity limits cannot be

cooled easily.

Oil is cooled with refrigeration chillers by passing chilled water in shell & tube or plate type heat exchanger. This process is expensive.

Another process is to pass oil in a finned type of heat exchanger.

Lobe Pump

Lobe pump is another type of positive displacement pump.

Why this type of pump is required in the industry.

This has sanitary construction ie it can be opened from one side by unscrewing backplate screws for cleaning.

Although it is supported only on one side by bearings it still manages to handle viscous liquids with ease.

Moreover, it has external bearing construction.

This type of construction allows it to handle liquid food applications without bearings/ bushes coming in contact with liquid/ semi-liquid.

For this reason, it is used in the pharma industry & preferred over other designs.

There are certain viscous liquids where it is advisable to not damage the crystals or chew them.

A lobe pump running on low rpm in such cases is an ideal solution.

Sometimes this pump is confused with a roots-type twin & three-lobe blower.

Although similar in construction the roots blower is used for pumping air for applications involving high-pressure low capacity air.

For section of suitable lobe blower following data are required.

1/Type of liquid to be pumped.

2/ Capacity in lpm, Lps, M3/ hr.

3/ Head to be developed.

4/viscosity of liquid.

Viscosity plays an important role in the selection of this type of pump.

Since other types of pumps are cheap solutions to low viscosity liquids the requirement of this type is for special applications.

It replaces the single screw pump with a rubber elastomer with robust construction & good life.

The timing gears on the stuffing box side relieve its rotors from touching with each other & the periphery of the pumping chamber.

It is advisable to run high viscosity liquids at low speed which allows suction end more time for the liquid to get into the pumping chamber.

Speed lowering devices include v belt drive, gearboxes, AC Drives.

Gear Pump uses

Gear Pumps are used for transfer of viscous & semi viscous liquids such as

  • Peanut Butter

  • Tomato Paste

  • Petroleum Jelly

  • Ink (paste)

  • Shampoo

  • Hand/Body Lotion

  • Plastisol

  • Oil-SAE

  • Spar Varnish

  • Soybean Oil

  • Maple Syrup

  • Oil

  • Corn Oil

  • Liquid Ink

  • Colognes/Perfumes

  • Sulphuric Acid

  • Gear Pumps are widely used in food & Pharmaceutical industries.

Application of Positive Displacement Pumps on different Industrial applications

Positive Displacement pumps comprise of the gear, piston or reciprocating pump, single screw, double screw, three screws, sliding wane, internal gear pumps.

why use positive displacement pumps?

Positive Displacement pumps are normally the preferred choice on viscus applications as the moving parts either gears or pistons, screws, impellers entrap liquid & transmit it at required pressure which is directly proportional to the bhp of the prime mover.

Since the clearances in the Positive Displacement pumps are less than their counterparts, the centrifugal pumps the savings in power are of such magnitude that pump cost is quickly recovered as payback to the end-user.

Power comes at a huge cost to the entrepreneur.

how cost-saving accrues?

Cost-saving can only be achieved if the correct pump is applied to the correct application.

We must always ensure to select an optimum solution on a given application.

In further topics, we shall elaborate on different pumps in various industrial applications.

Keep watching the write-up to understand Positive Displacement pumps.

What is NPSH (Net Positive Suction Head)

Net positive suction head available is the combined

effect of travel of liquid in a pipeline with losses due to friction, vertical direct loss, loss in the filter/ strainer & different types of bends & valves at a given viscosity.

Suction pipeline size is generally

a selection based on the flow rate of liquid at 1m/ second & the size of the pump.

Based on different types of pumps & their speeds

The liquid may travel at speeds ranging between 3 m/ sec to 5 meters per second.

Pumps are designed to work on speeds as per their inherent design & viscosity of the liquid to be handled.

Reciprocating positive displacement pumps have the lowest speeds as low as below 10 rpm to high speeds of flow in centrifugal machines up to 10000 rpm.

You cannot these days generalize about vacuum creation of the rotating machines due to developments in design.

You have to depend on the information given by manufacturers & the testing/ wetting of relevant consultants.

The Net positive suction head required (NPSHR) therefore depends on the design of the pumps.

To work the NPSHA should be greater than or equal to NPSHR.

Positive Displacement Pumps & NPSH (Net Positive Suction Head Available)

The consultant's role in recommending Positive Displacement Pumps is what most of the pump's lifeline as far as usage is concerned.

Although most of the pumps can be used on the majority of the applications.

The correctness of recommendations is based on consultants.

Sometimes the consultants are also referred by manufacturers so that their pumps find usage for an application.

Most of the time it has been found that lesser-known manufacturer although following same testing parameters suffers on account of recommendation of consultants. Whereas a consultant cannot be blamed for this as projects have to be executed in a specified time frame due to increasing costs.

Let’s talk about NPSHR for various types of pumps.

Let’s first talk about centrifugal pumps.

The bulk of the liquids is transferred by centrifugal pumps in various nomenclature although it has high NPSHR requirements.

But the ability to transfer high capacity cannot be matched by Positive displacement & other types of pumps.

However, the ability of positive displacement pumps is that these can create near absolute vacuum & therefore remain the first choice as far as viscous applications are concerned.

Not that centrifugal cannot perform this job but power consumption is very high.

We will continue the topic of NPSH again as it is so vast.