A、 Core metal material of hydraulic high-pressure piston pump

The pressure bearing components of high-pressure plunger pumps need to have high strength, corrosion resistance, and fatigue resistance, mainly using the following materials:

1. Cast iron: HT250 gray cast iron (ISO 185 standard) is used for the pump body base, with low cost and good shock absorption performance, but low pressure bearing capacity (≤ 25 MPa).

 

2. Stainless steel: commonly used 304 or 316 stainless steel (in accordance with ASTM A276 standard), with a yield strength of ≥ 205 MPa, suitable for corrosive media environments such as chemical or marine applications.

 

3. Alloy steel: such as 42CrMo (GB/T 3077 standard), with a hardness of HRC 28-32 after quenching and tempering treatment, used for high load components such as plungers and cylinder bodies.

 

B、 Auxiliary materials and process requirements

1. Surface treatment: Electroplating hard chromium (thickness 50-100 μ m) can improve the corrosion resistance of the plug, and the salt spray test has passed for 500 hours (ASTM B117).

2. Lubricating oil: It must meet the ISO VG 46 standard, with a viscosity index of ≥ 90, to ensure lubrication stability at high temperatures (80 ℃).

 

 

C、 Key sealing and wear-resistant materials

1. Wear resistant coating:

 

-Tungsten carbide (WC Co) plasma spray coating, with a hardness of ≥ 1200 HV, can extend the plunger life by more than three times (refer to the "Thermal Spray Technology Manual").

2. Sealing material:

 

-Polytetrafluoroethylene (PTFE): With a friction coefficient as low as 0.04 and a temperature resistance range of -200 ℃~260 ℃, it is suitable for dynamic sealing.

 

-Nitrile rubber (NBR): used for low-pressure sealing (pressure resistance ≤ 10 MPa), excellent oil resistance (compliant with ISO 3601-3 standard).

 

 

D、 Material selection and performance correlation

According to the recommendation of the American Hydraulic Association (NFPA/T2.6.1), the material combination should be matched with the working pressure (such as using integral alloy steel+PTFE composite seal when ≥ 50 MPa). In addition, the thermal expansion coefficient of the material (such as stainless steel 17.3 × 10 ⁻⁶/℃) needs to be coordinated with the design tolerance to avoid high-temperature leakage.

The above:Where is the sealing ring of the hydraulic piston pump? How to replace it