Frequently Asked Questions



Yes, our anticorrosive, non metallic, chemical pumps are 100% Make-in-India. Ansha Equipments Pvt. Ltd.guarantees the quality of the products. We design, manufacture, assemble and test our pumps for dangerous andcorrosive liquids in our own factory, which is located in Nashik. Moreover, all our anticorrosive chemical PP pump for acids parts are supplied only by Indian companies, which are carefully selected and qualified by us. We are ableto maintain such a high quality both by paying attention to every product detail and thanks to our designers andworkmen experience.


Ansha Equipments Pvt. has a wide distribution network all over India for anticorrosive non metallic PP pumps.Write to to find out which is the nearest Ansha Polyquip pumps distributor.



You can send Ansha Polyquip pumps for dangerous fluids to our workshop for repair or maintenance whenever youneed. You can write an e-mail to us at for more details. We can also send ourmaintenance executive to your workplace for diagnosing the issue.


Yes, all the spare parts of Ansha Polyquip standard anticorrosive chemical pumps are ready in stock, therefore weare able to guarantee a rapid and efficient service. The customer who needs to order the PP Pump’s spare parts canrequest a quotation, specifying the details of the required part. You can find the position number of the spare partsin the technical data sheets which are available on our website . For the not-standardpumps the spare parts will be supplied in a few days. You can write an e-mail to us at service@anshapolyquip.comfor more details.



Yes, every single acid pump used for acid transfer is tested by experienced personnel before being carefully packed anddispatched. Ansha Polyquip owns some test benches therefore we can check the correct functioning of our anticorrosive, non metallic chemical pumps. In this way we are able to maintain a high quality level in ourproduction. If the customer needs special tests or performance reports, he can request us when sending the enquiryor the order.


Ansha polyquip anticorrosive pumps for corrosive liquids are usually shipped with threaded flanges in addition andupon request

• Dry running protection devices. This device prevents expensive damage to pumps because it avoids the dry-running working, the closed discharge and the blocked suction.

• Flanges. Ansha Polyquip pumps for corrosive liquids are usually supplied with threaded connections(except for some pump models which are supplied flanged as standard). Upon request we can also supply differentkinds of flanges
• Baseplates. It is possible to have epoxy resin coated strong and chemically resistant base plates foranticorrosive PP Pumps which assure a perfectly horizontal and stable installation of the chemical pump in theplant.


Ansha Polyquip supplies many different chemical pumps for acids and dangerous liquids series, giving the customerthe opportunity to customize the pump according to his needs.
Our wide range of products includes:

- different kind of pumps suitable for pumping dangerous and corrosive liquids: two different pump materialsresistant to chemicals: PP pump (polypropylene) and PVDF Pump (polyvinylidene fluoride).
– different kind of o-rings and gaskets compatible with most of the existing chemicals.
– Other anticorrosive accessories for chemical pumps, including dry running protection devices, flanges andbaseplates, strainer, Pipes Bends, Hex Nipple, Nut bolts and washers.
Upon request, Ansha Polyquip can evaluate new projects for the design and production of special customizedpumps.


When you talk about chemical pumps for acids the choice of the material depends on different aspects. Our high-skilled personnel can help you in this evaluation by collecting some data about the kind of corrosive liquid you haveto pump, the concentration and temperature. Our chemical compatibility charts, created according to our decennialexperience, are very useful in these cases, but it’s necessary to perform a deep analysis of the final application andof the required performances in order to select the correct chemical pump model. Our technicians are alwaysavailable to select the correct pump and the best material for the customer’s application.


When you work with chemicals and dangerous liquids, it’s fundamental to select the right pump suitable for thecustomer’s application and required performances. Ansha Polyquip experienced personnel carefully evaluates thecustomer’s needs, paying attention to all the technical data. In particular, the following data are the most importantin order to choose the right pump: capacity/flow and head/pressure required, kind of liquid, concentration,temperature, viscosity, possible presence of solids in suspension and if known also NPSHa.

What is centrifugal pump?

Centrifugal process pumps are used to induct flow or raise a liquid from low to a high level. Centrifugal pumps require that the fluid be available to the pump section nozzle with sufficient energy normal centrifugal pumps cant suck on or draw the liquid into the pump housing. It you see a cross section of a typical centrifugal pump. You will find a section nozzle and a discharge nozzle and the principal pumping unit of a centrifugal pump is the volute and the impeller. The impeller is attach to a shaft the shaft spins and is powered by the motor or driver. The fluid enters into the eye of the impeller and is trapped between the impeller blades. The impeller blades contain the liquid and impart speed to the liquid as it passes from the impeller eye toward the outside diameter of the impeller. As the fluid accelerates in velocity the zone of low pressure is created in the eye of the impeller according to the Bernoulli principle so as velocity goes up pressure goes down. The liquid then leaves the outside diameter of the impeller at a high rate of speed which corresponds to the speed of the motor and then immediately slams into the internal casing wall of the valued. At this point the liquid the centrifugal velocity comes to an abrupt halt and the velocity is converted into pressure. The velocity goes down then the pressure goes up, because the motor is spinning there is also rotary velocity. The fluid is conducted from the cut water around the Internet volute housing in an ever increasing escape channel. As the pathway increases the rotary velocity decreases and even more energy and pressure is added to the liquid. The liquid leaves the pump a discharge pressure prepared to overcome the resistance in the system. The flow from a centrifugal pump is mostly governed by the speed of the driver and the height of the impeller blades. The pressure or head that these type of pumps can generate is mostly governed by the speed of the motor and the diameter of the impeller. Other factors play a lesser role in the pumps flow and pressure. Like the number pitch and thickness of the impeller blades.

What is pressure in centrifugal pump?

Pressure = Force / Area.

If we apply pressure to the surface of a liquid the pressure is transmitted uniformly in all directions across the surface and even through the liquid to the walls and bottom of the vessel containing the liquid

The pressure is expressed as Pounds Per Square Inch (psi)

Atmospheric Pressure(ATM) is the force exerted by the weight of the atmosphere on a unit of area atmospheric pressure is equal to 14.7 psi at sea level

Absolute pressure (psia) is the pressure measure it from a zero pressure reference. Absolute pressure is 17.7 psia sea level compound pressure gauges record absolute pressure measure it from a zero pressure

Gauge pressure (psig) is the pressure indicated on a simple pressure gauge. Simple pressure gauges establish an artificial zero reference at atmospheric pressure

psig = psia - ATM

Pump Head

The term pump head represents the net work performed on the liquid by the pump. Usually it refers to the maximum vertical distance from water source to discharge point that water can be pumped. It is the maximum limit, thepumpcan push the water vertically

There are four different sections of pump head

1. Static head (Hs)

2. Pressure head (HP)

3. Friction head (Hf)

4. Velocity head (Hv)

Head = Pressure / density

Specific gravity (

Specific gravity is the comparison of the density of liquid with the density of water. With pumps it is used to convert head into pressure the specific gravity formula = Density of the liquid / Density of water

The term head is the constant for the pump manufacturer. If a pump that generates 90 feet of head can elevate water, gasoline, caustic soda or any other liquid to a height of 90 feet. Since the manufacturer doesn't know the ultimate service of the pump in advance. Hence the term head is used as head in feet.

What is NPSH (Net Positive Section Head)?

When someone starts an industrial pump the tendency is to look towards a discharge piping and consider the discharge pressure and flow. We tend not to think about the section piping or the liquid coming into the eye of the impeller.

We need to emphasize the necessity to consider what's happening in this section of the pump.

This area is the source of problem and probably is responsible for about 40 percent of all pumps failure.

The Net positive section head or NPSH of pump is what the pump needs the minimum requirement to perform its duties. So NPSH is what happens in the section side of the pump including what goes on in the eye of the impeller.

NPSH in pump takes into consideration the below mentioned factors

Suction piping and connections

The elevation

The absolute pressure of the fluid in the suction piping

The velocity of the fluid

The temperature

These factors add energy to the fluid as it moves into the pump and others subtract energy from the fluid. There must be sufficient energy in the fluid for the impeller to convert this energy into pressure and flow. If the energy is inadequate then the pump suffers inadequate NPSH in simple terms.

To express the quantity of energy available in the liquid entering into the pump the unit of measure for NPSH is feet of head or feet of elevation in the pump section.

What is pump NPSHa (Net Positive Section Head available) and NPSHr (Net Positive Section Head required)?

Every system, meaning all pipes tanks and connection on the section side of the pump has its own NPSHa or the net positive section had available there should always be more suction . had available in the system than section had required of the pump.

NPSHr (Net Positive Section Head required)

The net positive section head required is the energy in the liquid required to overcome the friction losses from the suction nozzle to the eye of the impeller without causing vaporization It is a characteristic of the pump and is indicated on the pumps curve it varies by design by size and by operating conditions it is determined by a lift test producing and negative pressure in inches of mercury and then converted into feed of required NPSH an easy way to understand NPSHR is to call it the minimum suction pressure necessary to keep the pump fluid in the liquid state according to the standards of the hydraulic Institute a suction lift test is performed on the pump and the pressure in the section vessel is lowered to the point where the pump suffers a 3 percent loss in total head this point is called the NPSHr of the pump

Mentioned below the formula for calculating NPSHr

NPSHr = ATM + Pgs +Hv – Hvp

ATM = Atmospheric pressure at the elevation of the installation expressed in feet of head

Pgs = The suction pressure gauge reading taken at the pump center line and converted and two feet of head

Hv = velocity head = V^2 / 2g [velocity squared divided by two g and the velocity here is the velocity of the fluid moving through the pipes measure it in feet per second and g is the acceleration of gravity taken as 32.16 feet per second.

Hvp =  The vapour pressure of the fluid expressed in feet of head.

NPSHa (Net Positive Section Head available)

The net positive section head available is the energy in the fluid at the section connection of the pump over and above the liquid is vapour pressure. It is a characteristic of the system and we say that the NPSHa should be greater than the end NPSHr.

NPSHa = Ha + Hs – Hvp Hf - Hi

HA = Atmospheric head (equal 33.9 feet at sea level)

HS = Static had expressed in feet of the fluid level in the section vessel to the pump centre line

Hvp = The vapour pressure of the fluid expressed in feet of head.

HF = Friction losses expressed in feet in the section piping and connections

HI = Inlet head or the losses expressed in feed.

What is Cavitation in pump?

Cravitation is the formation and subsequent collapse or implosion of vapour bubbles inside the pump. It occurs because the absolute pressure on the liquid falls below the liquid is vapour pressure when the vapour bubbles collapse with enough frequency. If the vapour bubbles collapse with enough energy they can remove metal from the internal casing wall and the impeller blades, and they will live dent marks. Cravitation could occur in other parts of the pumping system under the some circumstances valves and pipe elbows can also suffer damage from cavitation. Cavitation can have impact on efficiency of pump. It can also cause sudden surges in flow and pressure at the discharge nozzle. The calculation of pump NPSHr and NPSHa is based on an understanding of the liquid is absolute vapour pressure. The effects of cavitation are noise and vibration in the first stage. If the pump operates and the cavitating conditions for enough time the following can occur.

Pitting marks on the impeller blades and on the Internet valued casing wall of the pump.

Bearing failure

Shaft breakage and other fatigue failures in the pump

Premature mechanical seal failure

Cavitation can happen due to following

Reduction of pressure at the section nozzle

Increase of the temperature of the pump liquid

Increase in the velocity or flow of the fluid.

Separation and reduction of the flow due to a change in the viscosity of the liquid

Undesirable flow conditions caused by obstructions or sharp elbows in the section piping.

The focus should be on resolving capitation problems by increasing the external pressure on the fluid or decreasing its vapour pressure the external pressure could be increased by increasing the pressure at the pump section or reducing the energy losses at the entrance to the pump or by using a larger pump. And the vapour pressure of the fluid is decreased by lowering the temperature of the fluid or by changing to a fluid with a lower vapour pressure sometimes simply removing the aspirated air by venting the pump will have the same effect.

Why non metallic pumps are used?

Often stainless steel pumps cannot handle corrosive chemicals such as acids, alkalis and solvents. Hence specifically designed Polypropylene pumps (PP Pump) or polyvinylidene fluoride pumps (PVDF Pump) are used as chemical transfer pumps in chemical processing, water treatment, plating applications and more. PP and PVDF Pumps are capable of handling Fresh Water, Salt Water, DI Water, CitricAcid, Fluosilicic Acid, Formaldehyde, Muriatic Acid, Nitric Acid, Phosphoric Acid, Potassium Hydroxide, Potassium Permanganate, Sodium Hydroxide,Sulfuric Acid, and many more.

Since these chemical feed pump or chemical process pump are anticorrosive in nature they can transfer corrosive liquid efficiently. The polypropylene pump can be used as Filter press pump.

The PP Vertical pumps are used in Effluent Treatment Plant (ETP plant) as ETP Pump and in Sewage Treatment Plant (STP) as STP Pumps.  These ETP Pumps and STP pumps are manufactured using high-grade Polypropylene or polyvinylidene fluoride. It is mandatory to treat the waste water for all the industries under environment protection norms.