Product Introduction of Wear-resistant Discs
Wear-resistant discs are important components in the hydraulic end cylinder liner installation system of drilling mud pumps. They are usually installed at relevant positions between the hydraulic cylinder and the cylinder liner, as well as the cylinder liner flange. Together with the cylinder liner seal, cylinder liner flange, cylinder liner cover and cylinder liner, they form the cylinder liner installation and sealing structure.
In some F series mud pump structures, the wear-resistant plate is installed on the rear mounting surface of the hydraulic end, providing positioning, support and wear-resistant working surfaces for the cylinder liner seal and cylinder liner. Its existence can prevent excessive wear on the relevant installation surfaces of the liquid cylinder body directly during the installation, disassembly and long-term operation of the cylinder liner.
Wear-resistant discs are replaceable hydraulic end structural components. When wear, erosion or damage occurs on the sealing mating surface, positioning holes or load-bearing end face, the installation and sealing conditions of the cylinder liner area can be restored by replacing the wear-resistant disc, thereby reducing the difficulty of directly repairing the cylinder body.
The main function of the wear-resistant plate
1. Protect the installation surface of the hydraulic cylinder: The wear-resistant plate is arranged between the cylinder liner and the related installation structure of the hydraulic end, transferring part of the assembly contact, disassembly wear and operating load to the replaceable parts, reducing the direct wear of the installation surface of the hydraulic cylinder body.
2. Provide positioning basis for the cylinder liner: The center hole, end face and related steps of the wear-resistant disc cooperate with the cylinder liner installation structure to help maintain the correct radial and axial installation positions of the cylinder liner.
3. Supporting cylinder liner seal: In the corresponding mud pump structure, the cylinder liner seal is installed in the cavity, counterbore or mating position of the wear-resistant plate, which provides stable installation and compression support conditions for the seal.
4. Transfer the load for cylinder liner installation: After the cylinder liner cover and the cylinder liner flange are axially compressed, the wear-resistant disc, as part of the cylinder liner installation system, bears and transmits the corresponding structural load.
The installation relationship of wear-resistant discs in the cylinder liner system
In the typical F series mud pump cylinder liner installation structure, the wear-resistant plate is installed at the corresponding installation position on the rear side of the hydraulic end body, the cylinder liner flange is set on its outside, and the cylinder liner seal is installed in the corresponding sealing cavity or counterbore position of the wear-resistant plate.
After the cylinder liner is inserted, axial locking is formed through the cylinder liner cover, cylinder liner locking ring and cylinder liner flange. The wear-resistant disc is located between the hydraulic cylinder and the cylinder liner system, providing a basis for installation, positioning and sealing.
Therefore, although the name of the wear-resistant disc contains the word "wear-resistant", its function is not to work by friction like brake discs or friction plates, but to serve as a dedicated replaceable installation and protection part for the hydraulic end of the mud pump.
The relationship with cylinder liner sealing
The wear-resistant disc itself is usually not the main elastic sealing element. In the corresponding structure, the cylinder liner seal is installed at the specified position between the wear-resistant disc and the liquid cylinder and cylinder liner, and forms a static seal through compression.
One of the important functions of the wear-resistant disc is to provide a dimensionally stable installation groove, counterbore or support surface for the cylinder liner seal. If the sealing cavity of the wear-resistant disc is eroded, scratched, corroded or deformed, even if a new cylinder liner seal is replaced, unstable sealing or leakage may still occur.
Therefore, when inspecting the leakage at the cylinder liner position, in addition to checking the cylinder liner seal, the sealing mating surface of the wear-resistant disc and the installation surface of the liquid cylinder should also be inspected simultaneously.
The difference from the cylinder liner flange
Wear-resistant disc: Located between the liquid cylinder and the cylinder liner installation system, it mainly undertakes the functions of protecting the installation surface, positioning the cylinder liner, providing sealing support and transmitting local loads.
Cylinder liner flange: It is usually fixed on the outside of the wear-resistant plate or at the corresponding position of the hydraulic end, providing installation threads and a structural load-bearing foundation for the cylinder liner cover.
Cylinder liner gland: Connected to the cylinder liner flange, it generates and maintains the axial clamping force of the cylinder liner.
The three belong to the same cylinder liner installation system, but their structures and functions are completely different. When purchasing, they should be confirmed respectively according to the original part numbers and mating dimensions.
Central hole and sealing cavity
The center hole and internal steps of the wear-resistant plate are key mating dimensions. The center hole needs to match the external installation structure of the cylinder liner, and at the same time ensure that the cylinder liner can correctly enter the hydraulic end and maintain the installation center.
For wear-resistant discs with cylinder liner sealing counterholes or sealing positioning steps, it is also necessary to focus on confirming the diameter, depth of the sealing cavity, the position of the steps and the effective support width.
If the wear of the center hole expands or the sealing cavity undergoes uneven wear, it may cause poor positioning of the cylinder liner and affect the compression state and working life of the sealing parts.
The relationship between installation holes and positioning
Some of the wear-resistant discs of the mud pump are positioned and fixed through the hydraulic end studs or installation holes, and the cylinder liner flanges are then installed on the corresponding studs. Therefore, the number, diameter, hole spacing and distribution position of the installation holes of the wear-resistant disc must be exactly matched with the hydraulic end.
If there is a deviation in the position of the installation hole, it should not be dealt with by increasing the hole diameter or forcing the assembly, otherwise it may damage the center position of the wear-resistant disc, and thereby affect the coaxial relationship between the cylinder liner and the piston.
Wear resistance and protective features
The wear-resistant disc is constantly exposed to the hydraulic end working environment of the mud pump. Besides mechanical contact and axial loads, it may also be affected by drilling fluid, moisture and corrosive media.
Different manufacturers will adopt different materials, heat treatments or surface protection processes according to specific pump types and technical requirements. In the public information of mud pump accessories, one can see schemes such as alloy steel forgings and surface coatings. However, when actually supplying, the raw material specifications and technical drawings of the corresponding pump type should still be taken as the standard.
Common Failures and Inspections
When inspecting the wear-resistant disc, special attention should be paid to checking the center hole, the positioning surface of the cylinder liner, the sealing countersunk hole, the load-bearing end face, the installation hole and the installation surface in contact with the liquid cylinder.
Common abnormalities include end face wear, erosion of the sealing cavity, wear of the center hole, local corrosion, indentations, scratches, wear of the installation hole, as well as deformation or cracking of the main body.
If the cylinder liner seal fails frequently, or if the cylinder liner is skewed or loose after installation, it is necessary to check whether the wear-resistant disc has suffered excessive wear. It is not advisable to merely repeatedly replace the cylinder liner seal or increase the tightness of the cylinder liner gland.
Key points for selection
When purchasing wear-resistant discs for drilling mud pumps, it is recommended to focus on confirming the following information:
1. Brand, series and specific model of mud pump;
2. Hydraulic end or hydraulic cylinder model;
3. Specifications of the matching cylinder liner and external installation dimensions;
4. Matching cylinder liner seal model;
5. Outer diameter and total thickness of the wear-resistant disc;
6. Central hole diameter;
7. Diameter of the sealed counterbore or positioning step;
8. Depth of the sealed cavity and position of the steps;
9. Number and diameter of installation holes;
10. Center distance and distribution dimensions of installation holes;
11. Positioning structure of the contact surface with the liquid cylinder;
12. Matching cylinder liner flange model;
13. Original part number, physical sample or technical drawing.
Installation and Maintenance
Before installation, the installation surface of the hydraulic end, the end faces on both sides of the wear-resistant plate, the center hole, the sealing countersunk hole and the installation hole should be thoroughly cleaned to remove mud, rust, residues of old seals and metal particles.
When installing the wear-resistant plate, make sure it is fully in contact with the positioning surface of the hydraulic end, and the installation holes are correctly aligned with the studs or fixed holes. No foreign objects should be trapped or lifted on one side.
Before installing the cylinder liner seal, it is necessary to check whether there are burrs, scratches and obvious corrosion in the sealing cavity of the wear-resistant disc to avoid the new seal being cut during the assembly process.
Subsequently, install the cylinder liner flange, cylinder liner seal, cylinder liner and cylinder liner compression parts in the corresponding assembly sequence of the mud pump. The specific fastening method and parameters should be carried out in accordance with the maintenance data of the corresponding pump type.
Procurement Instructions
Juli Petroleum Drilling and Production Equipment Co., Ltd. provides wear-resistant discs and hydraulic end cylinder liner system accessories for drilling mud pumps. Wear-resistant discs are mainly used to protect the installation surface of the hydraulic end cylinder liner and provide a supporting foundation for the positioning and sealing of the cylinder liner. There are differences among various models of mud pumps in terms of the outer diameter, thickness, center hole, seal counterbore, installation hole and positioning structure of the wear-resistant plate. When purchasing, it is recommended to provide the model of the mud pump, the model of the hydraulic end, the specifications of the cylinder liner and seal, the original part number, the physical dimensions or technical drawings for matching verification.