HOT OIL PUMP

Volcano hot oil pump material

Hot oil pump body materials are mainly cast iron, steel, cast steel, bronze, composite materials, carbon structural steel, alloy steel, and non-metallic materials. These parameters should be considered choosing materials: strength, corrosion resistance, erosion resistance, casting and machining performance, weld repair performance, and cost.

1. Cast iron hot oil pump

For most liquid transportations, grey cast iron is a reasonable choice for pump housing. Grey cast iron is strong enough to withstand the pressure in the single-stage pumps. Ductile iron is widely used in the normal pressure and temperature range. In cases where grey cast iron and ductile iron are not strong enough to withstand erosion, cast iron with a high percentage of nickel is mainly used as the pump body material. Recently, a new type of corrosion-resistant nickel cast iron material (called D2W) with good welding performance has been developed, containing a minuscule amount of niobium to improve welding performance. Common austenitic cast iron usually contains 15.92% nickel and is widely used in the brine.

Gray cast iron is the most widely used cast iron and its Iranian national standard code is HT. commonly, the pump body, pump impeller cover, suspension, and clean water centrifugal pumps are made of this material and three grades HT150, HT200, and HT250 are mostly utilized. HT150 is often used for subsidiary parts such as base and back plate, pump body, pump cover, suspension, etc. more than HT200, while main parts such as impellers, spigots, bushings, etc. are usually made of HT250. The presentation of gray cast iron is different from country to country. For instant, Japan’s codename is FC, Germany’s codename is GG, and the United States codename is Cass4.

Nodular cast iron is a type of cast iron with better overall performance and its Iranian national standard code is QT. Since its mechanical properties are close to steel and its casting and processing properties are better than steel, it is usually used as a substitute for cast steel. The most common grades used are QT450-10, QT500-7, and QT600-3. Due to the limitations of casting and other reasons, the current water pump impeller is made of this material, especially the open-cutting type impeller. The DN standard describes ductile iron as GGG, and American Express called it ductile iron.

2. Steel hot oil pump

The most widely used stainless steel is austenitic stainless steel. Austenitic stainless steel is a strong corrosion-resistant material in the diluted HCl and H2SO4 fluids for the chemical injection pumps. Additionally, other ideal corrosion-resistant materials are high-alloy stainless steel (alloy 20) and double stainless steel.

3. Cast steel

In the case of corrosive and harmful petroleum products, or when the multi-stage pump outlet pressure reaches 13.8MPa, it is necessary to use cast steel or cast stainless steel. In boiler feed water pumps and many hydrocarbon applications, martensitic stainless steel is often used. Martensitic stainless steel has suitable mechanical properties and is applicable for high working pressure conditions, but its corrosion resistance is not as proper as other types of stainless steel in chemical and other corrosive environments.

Austenitic stainless steel (CF-8M, CF-3M, etc.) is often used as pump casing material. In addition, austenitic stainless steel can resist corrosion due to its high speed and is relatively easy to weld in place. High-pressure shallow water injection pumps have higher requirements for corrosion resistance and mechanical properties. The pump body is made of duplex stainless steel (50% ferrite + 50% austenite). Since the cast steel strength is modified by combining other alloys, pressure-bearing parts are cast steel, mostly when the pressure exceeds 16MPa. The national Iranian standard code is ZG, the most commonly used grade is ZG230-450. Japan, as well as the United States, usually use CS to show cast steel.

4. Carbon structural steel

It is usually divided into Katong carbon structural steel and high-quality carbon structural steel. The representative of carbon structural steel is Q235, which is mostly used in various steel plates and section steels. The representative of high-quality carbon steel is No. 45 steel, which is widely used as a pump shaft material in the absence of corrosion.

5. Alloy steel

The most prominent alloy steel is Cr40, which is usually used as a material for high-strength pump shafts.

6. Non-metallic materials

Non-metallic materials for pumps are mainly used for sealing, such as polytetrafluoroethylene, fluorine rubber, nitrile rubber, etc., among these non-metallic materials, polytetrafluoroethylene has excellent corrosion resistance as well as high-temperature resistance, and suitable for chemical pump gaskets and mechanical seals are used. It is applicable for almost all chemical environments up to 250°C. Its disadvantages are high hardness and difficulty in assembly.

Fluorine rubber is also a kind of temperature-resistant and corrosion-resistant material. The working temperature is less than 160 degrees. When the user does not have a particular need, the company’s chemical pumps all use the sealing ring of this material. While nitrile rubber is mainly used for oil resistance or static sealing for a clean water environment.

7. Bronze

In many water pump applications, bronze material is used as the pump housing. Lead bronze is usually utilized in low-pressure small pumps, where the lead helps to seal the pump housing. However, tin bronze is applied as the centrifugal pump housing material in bigger pumps. Although Nickel aluminum bronze shows the best mechanical performance and corrosion resistance, it is costly and not competitive.