Progressive Cavity Pump Stator
Various materials, Customizable
It can replace most brands of progressive cavity pumps (also called eccentric screw pumps).
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What is a
stator of progressive cavity pump ?
The stator of the progressive cavity pump is one of the important main parts of progressive cavity pump, also known as the progressive cavity pump bushing;
The material is usually divided into two categories:
1. Use inelastic hard materials such as metals, plastics, and ceramics;
2. Use rubber-like elastic materials (including a small amount of elastic plastic).
At present, most domestic and foreign stators are rubber-based stators;
The rotor driven by the external power source meshes with the stator to form a sealed cavity that separates the suction cavity and the discharge cavity, so that the pump can work effectively.
Table A – Physical properties of rubber
| Performance | Natural rubber (NR) | Nitrile rubber (NBR) | Chloroprene rubber (CR) | Butyl rubber (IIR) | EPDM | Chlorinated polyethylene (CSM) | Chlorohydrin glue (CHR) | Acrylic resin glue (ACM) | Chlorinated rubber (EPM) | Polyurethane rubber (Pu) |
|---|---|---|---|---|---|---|---|---|---|---|
| Vulcanized rubber hardness [Shore (A)] | 30 ~ 95 | 30 ~ 100 | 40 ~ 90 | 40 ~ 85 | 30 ~ 85 | 50 ~ 95 | 40 ~ 90 | 60 ~ 80 | 60 ~ 80 | > 30 |
| Tensile strength /Mpa | < 18 | < 20 | < 20 | < 16 | < 20 | < 16 | < 18 | < 13 | < 12 | < 40 |
| Operating temperature range /℃ | -55 ~ 100 | -30 ~ 120 | -20 ~ 120 | -40 ~ 150 | -50 ~ 150 | -30 ~ 125 | -40 ~ 150 | -20 ~ 200 | -20 ~ 250 | -20 ~ 80 |
| Elongation | ● | ○ | ● | △ | ○ | ○ | ○ | △ | ○ | ● |
| Elasticity | ● | ○ | ○ | × | ○ | △ | ○ | ○ | △ | ● |
| Compression set resistance | ● | ● | ○ | △ | ○ | ○ | △ | ● | ● | ● |
| Tear resistance | ● | ○ | ○ | ○ | ○ | ○ | ○ | ○ | ○ | ● |
| Wear resistance | ● | ● | ○ | △ | ○ | ○ | ○ | ● | ● | ● |
| Aging resistance | △ | ○ | ○ | ● | ● | ● | ● | ○ | ● | △ |
| Flexibility | ● | ○ | ● | ● | ○ | ● | ○ | △ | ● | ● |
| Heat resistance | △ | ○ | ○ | ● | ● | ○ | ● | ● | ● | △ |
| Water resistance | ● | ○ | ● | ● | ● | ● | ● | × | ● | × |
| Dynamic characteristics | ● | ○ | △ | × | ○ | △ | ○ | ○ | △ | ● |
| Best performance | Good elasticity, high strength, good low temperature performance and optimal dynamic performance | Turbidity and heat resistance | Acid and alkali resistance, water resistance, ozone resistance, self extinguishing | Water resistance, steam resistance, good air tightness | Aging resistance, chemical resistance, insulation, temperature resistance | Aging resistance, ozone resistance, chemical resistance | Heat resistance, cold resistance, good solvent resistance | High temperature resistant oil, halogen resistant, heat resistant | High temperature resistance, excellent media resistance | Optimal wear resistance, high lightness, high elasticity |
Note: ●: Excellent performance ○: Good performance △: Poor performance ×: Very poor performance
Table B – Rubber’s media resistance table
| Material | Maximum temperature | Suitable media | Unsuitable media |
|---|---|---|---|
| Natural rubber (NR) | 70 ℃ | Mixture of abrasive substances, mixed liquid of organic matter, acid, alcohol, acetaldehyde, mud, cement slurry, cement | Ozone, concentrated acids, fats, oils, hydrocarbons (methane, ethylene, benzene) |
| Nitrile rubber (NBR) | 90 ℃ | Hydrocarbons, weak acids, weak bases, light gasoline, mineral oils, animal and vegetable oils, fats, lubricants | Aromatic hydrocarbons (substances with benzene), chlorohydrocarbons, esters, acetaldehydes, ketones, ozone, strong acids |
| Chloroprene rubber (CR) | 90 ℃ | Ozone, fat, paraffin-based lubricating oil, volatile lubricating oil, fatty hydrocarbon, reducing agent, salt solution | Strong acids, ketones, esters, aromatic hydrocarbons, chlorohydrocarbons, aromatic lubricants, acetic acid |
| Fluorosulfonylated polyethylene glue | 110 ℃ | Alcohol, salt solution, ammonia, acid chemicals, oil, bleach, disinfectant, paper, mud, chromic acid | Strong acid, crude oil, tar, aromatic carbon compound, chlorohydrocarbon |
| Fluororubber (EPM) | 180 ℃ | Aliphatic hydrocarbons, aromatic hydrocarbons, halogen hydrocarbons, oils, fats, acids | Ketones, esters |
| Ethylene | 110 ℃ | Ozone, hot water, strong sulfuric acid, nitric acid, animal and vegetable oils, fats | Petroleum, solvent, benzene, aromatic hydrocarbon, light oil, tar |
| Chloroprene rubber (VE) | 120 ℃ | Mineral oil (high temperature), animal and vegetable food oil, latex, rubber, paste-like solvent | Water, aromatic hydrocarbons, alcohol, ketones, alkalis, acids |
| Sodium rubber | 80 ℃ | Sewage, abrasive material mixed liquid, acid sludge, ammonia, inorganic sewage mixed liquid | Same as natural rubber, other ketones and fats |
| Butyl rubber (IIR) | 110 ℃ | Animal and vegetable oils, oils, fats, ozone, strong acidification drugs, acids, alkalis | Petroleum, solvents, benzene, aromatic hydrocarbons, light gasoline, lubricating oil |
Progressive cavity pump stator manufacturing steps :
- Rubber mixing
- Cutting
- Machining stator blanks (seamless steel tubes)
- Treat the surface of the inner hole of the stator blank
- Combine stator blank and stator mold
- Injection rubber
- Vulcanization
- Disassemble the stator mold
- Finishing
- Paint and packaging
How to install the progressive cavity pump stator ?
- After the rotor and pump body are installed, the inner cavity of the stator and the surface of the rotor need to be coated with lubricant or dimethyl silicone oil;
- Fix the stator with tooling (can be chain clamp, pipe clamp or special fixing tool);
- One person fixes the stator and one person clockwise disc pump (it is standard to stand on the pump drive end and look towards the water outlet), and sleeve the stator into the rotor until the fit is complete;
- Install the buttress so that the stator and rotor are on the same horizontal line；
- Install four long bolts and material-out chamber.
How to disassemble the progressive cavity pump stator ?
- Inject lubricating medium or dimethyl silicone oil from the end of the stator (Material-out chamber);
- Rotate the drive shaft or coupling clockwise 3-5 times to make the lubricating medium fill the entire cavity of the stator;
- Loosen the four long bolts, and remove the discharge body and buttress;
- Fix the stator with tooling (can be chain clamp, pipe clamp or special fixing tool);
- One person fixes the stator and pulls it out, and one person counterclockwise discs the drive shaft or coupling to make the stator withdraw.
- So far, the stator has been disassembled.
Frequently Asked Question
1. Natural Wear:
Since the stator and rotor are interference fit (sometimes the medium contains solid particles), these conditions are fixed, so in the actual operation process, it will be purely natural wear.
2. Unnatural Wear:
The pump is reversed and idling causes dry operation (the medium is not filled with the medium or the material is interrupted during the operation), and the medium enters the hard foreign matter.
The front end is the same as the rear end:
The suction end is the same as the discharge end, and there is no distinction between front and rear.
The front end is different from the slender:
An oval section with a bell mouth at one end; the bell mouth is the take-out end, and the ellipse is the discharge end.