Product Introduction of Cylinder Liner Locking Ring
The cylinder liner locking ring is a positioning and locking accessory in the hydraulic end cylinder liner installation system of the drilling mud pump. It is usually used together with the cylinder liner, cylinder liner cover, cylinder liner flange and the matching O-ring and other parts. Its main function is to form a reliable axial limit and mechanical locking relationship after the cylinder liner is installed, helping the cylinder liner gland to stably keep the cylinder liner at the specified installation position.
In the structures of some F series and other drilling mud pumps, the cylinder liner locking ring adopts a split structure composed of two semi-rings. After the two semi-rings are installed in the corresponding ring grooves of the cylinder liner, the matching O-rings are used to keep the semi-rings in the installation position. Then, together with the cylinder liner cover, the installation and locking of the cylinder liner are completed.
The locking structures of cylinder liners for different brands and models of mud pumps are not exactly the same. The inner diameter, outer diameter, thickness, groove shape, split structure of the locking ring and the specifications of the matching O-rings should all be determined according to the original equipment and cannot be replaced merely based on the inner diameter or external dimensions of the cylinder liner.
The main function of the cylinder liner locking ring
1. Axial limit of cylinder liner: The locking ring is installed in the corresponding positioning groove or locking position of the cylinder liner, forming a mechanical fit with the cylinder liner cover to restrict the abnormal movement of the cylinder liner in the axial direction.
2. Transmitting the clamping force of the cylinder liner cover: In the corresponding structure, the cylinder liner cover transmits axial clamping and holding force to the cylinder liner through the locking ring, ensuring that the cylinder liner is stably installed at the specified position at the hydraulic end.
3. Maintain the installation position of the cylinder liner: During the operation of the mud pump, the cylinder liner and the piston working pair are subjected to periodic loads and vibrations. The locking ring, together with the cover, cylinder liner and installation structure, keeps the position of the cylinder liner stable.
4. Facilitates the disassembly and assembly of cylinder liners: The split lock ring can be disassembled under the corresponding structure, facilitating the maintenance and replacement of cylinder liners, pistons and cylinder liner seals.
Split locking structure
The cylinder liner locking rings of some drilling mud pumps are not a complete closed ring but are composed of two semi-circular rings. When installing, the two semi-rings respectively enter the corresponding ring grooves or positioning positions of the cylinder liner. After combination, a complete annular limit structure is formed.
This structure facilitates installation and disassembly without inserting a complete ring from the end of the cylinder liner, making it particularly suitable for maintenance operations of the mud pump cylinder liner system.
The inner working surfaces, end faces and external profiles of the two semi-rings need to be correctly matched with the cylinder liner and the cylinder liner gland. If the size of the locking ring is incorrect or it does not fully enter the positioning groove, it may cause the gland to fail to be correctly pressed or the axial positioning of the cylinder liner to be abnormal.
The fit between the locking ring and the O-ring
In some mud pump structures, a ring groove is set on the outer circle of the cylinder liner locking ring. After installing the matching O-ring, the two semi-locking rings are kept together to prevent the semi-rings from deviating from the correct position during the installation of the cylinder liner cover.
The main task of the O-ring here is usually to assist in maintaining the combined state of the two semi-rings, and it cannot be simply understood as the main sealing component of the high-pressure working chamber of the cylinder liner. The specific function of the O-ring should still be confirmed according to the corresponding pump type structure.
If the O-rings are found to be aged, broken, lose elasticity or have size mismatches during maintenance, they should be replaced in accordance with the original equipment requirements to prevent the locking rings from shifting during assembly.
The difference from the cylinder liner gland
Cylinder liner locking ring: It mainly cooperates with the positioning position on the cylinder liner to form an axial limit and lock the force-bearing part.
Cylinder liner gland: It is usually connected to the cylinder liner flange or the corresponding mounting seat through large-diameter threads, and after being tightened, it generates an axial compression effect.
Two parts work together in some mud pump structures: the cylinder liner gland provides axial compression, while the cylinder liner locking ring forms a force-bearing and limit structure at the corresponding position of the cylinder liner. Therefore, the two cannot be purchased as the same type of parts just because they both have a "locking" function.
The difference from the cylinder liner sealing ring
The cylinder liner locking ring is a mechanical positioning and locking part, and its main task is not to directly complete the sealing of the working medium at the hydraulic end.
Cylinder liner locking ring: Responsible for mechanical limit, locking and load transmission.
Cylinder liner sealing ring: Installed in the liquid cylinder, wear-resistant plate or corresponding sealing position, it is mainly responsible for the static sealing of the cylinder liner installation part.
Therefore, when leakage occurs at the cylinder liner position, it is not only necessary to check the locking ring, but also to inspect the cylinder liner sealing ring, sealing groove, wear-resistant plate and related sealing surfaces.
Key fit dimensions
The key to the cylinder liner locking ring is not the two dimensions of the inner and outer diameters of the ordinary ring. For split lock rings, it is also necessary to confirm the thickness of the lock ring, the inner positioning profile, the fit dimensions with the cylinder liner ring groove, the external load-bearing profile, and the O-ring installation groove and other structures.
If the thickness or groove shape of the locking ring is incorrect, even if it can be installed on the cylinder liner, it may change the axial relationship between the cylinder liner cover and the locking ring, resulting in abnormal installation position of the cover or incorrect pre-tightening state of the cylinder liner.
Common Failures and Inspections
When inspecting the cylinder liner lock ring, the working end face, the inner positioning surface, the split end face, the O-ring groove and the overall structure should be inspected with emphasis.
Common abnormalities include wear on the working surface, local indentations, edge chipping, plastic deformation, corrosion, cracks, and damage to O-ring grooves, etc.
If the cylinder liner shows axial loosening or the gland cannot maintain the correct locking state, in addition to checking the locking ring, the cylinder liner positioning groove, cylinder liner gland, cylinder liner flange and related thread structure should also be inspected simultaneously.
Key points for selection
When purchasing the locking ring of the drilling mud pump cylinder liner, 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. Cylinder liner model and external installation structure;
4. Cylinder liner cover model;
5. Inner and outer diameters of the locking ring;
6. Thickness and axial dimensions of the locking ring;
7. Contour dimensions that fit with the cylinder liner positioning groove;
8. Split form and semi-ring structure;
9. Dimensions of the O-ring groove on the outer circle;
10. Specifications of matching O-rings;
11. Original part number, physical sample or technical drawing.
Installation and Maintenance
Before installation, the locking ring of the cylinder liner, the positioning groove of the cylinder liner and the internal mating position of the cylinder liner gland should be cleaned, and mud, rust and metal particles should be removed.
For split locking rings, it should be confirmed that both half rings have fully entered the specified positioning positions of the cylinder liner, and the matching O-rings should be installed according to the original equipment structure to prevent the half rings from dislocating during subsequent installation.
Before installing the cylinder liner gland, it should be confirmed again that the locking ring is not lifted, misaligned or has foreign objects trapped in it. The locking ring that is not correctly positioned should not be pressed in by forcibly tightening the cylinder liner cover.
If the locking ring has cracks, severe indentations, obvious deformations or the positioning working surface is damaged, it should be replaced in accordance with the equipment maintenance requirements. Before disassembly and assembly, the pump should be stopped and it should be confirmed that the hydraulic end has been safely depressurized.
Procurement Instructions
Juli Petroleum Drilling and Production Equipment Co., Ltd. provides cylinder liner locking rings and accessories for drilling mud pump cylinder liner systems. The cylinder liner locking ring is mainly used in conjunction with the cylinder liner, cylinder liner cover and the matching O-ring, for the axial limit and locking of the cylinder liner. There are differences in the inner and outer diameters, thickness, split structure, positioning profile and O-ring grooves of the locking rings of different mud pumps. When purchasing, it is recommended to provide the model of the mud pump, cylinder liner model, cylinder liner cover model, original part number, physical dimensions or technical drawings for matching verification.