Product Introduction of the plug-in board assembly
The plug plate assembly is a positioning and supporting accessory in the hydraulic end valve group system of the drilling mud pump. It is mainly installed inside the hydraulic cylinder and is used to correct, position and fix the lower valve stem guide, so that the valve stem guide structure can maintain the correct installation position and center relationship.
In some F series drilling mud pumps, the baffle assembly is located at the relevant positioning position inside the valve group, and together with the lower valve stem guide, valve spring, valve body and cylinder structure, it forms the installation and guidance system of the valve group. When inspecting the valve assembly, after removing the plug plate assembly, the lower valve stem guide, valve spring and valve body and other parts can be further taken out.
The plug plate assembly is neither a valve group seal nor a spring element that directly controls the opening and closing of the valve. Its core function is to establish a reliable mechanical positioning and support relationship, maintain the stable position of the lower valve stem guide, and thereby assist the valve body in opening and returning to its original position along the specified axis.
The main function of the board insertion assembly
1. Fix the lower valve stem guide: The plug plate assembly fixes the lower valve stem guide through its own positioning surface and supporting structure to prevent unnecessary movement of the guide during the operation of the mud pump.
2. Maintain the center position of the guide: The lower valve stem guide is responsible for limiting the radial swing of the valve stem, while the plug plate assembly provides the correct installation foundation for the guide, which helps to maintain the center relationship among the valve stem, valve body and valve seat.
3. Bear local support loads: When the mud pump valve group is frequently opened and closed, the guide vane will be subjected to periodic mechanical actions. The baffle assembly needs to maintain the stability of the corresponding support position and bear the local loads transmitted by the guiding structure.
4. Facilitates disassembly, assembly and maintenance of the valve assembly: The plug-in plate assembly is a detachable valve assembly positioning part. After removal, it can provide a passage for the inspection and replacement of internal parts such as the lower valve stem guide, valve spring and valve body.
Structural composition
The insert plate assemblies used in some F1300, F1600 and other drilling mud pumps can be composed of insert plates and matching copper blocks and other parts. The insert plate serves as the main positioning and load-bearing component, while the copper block participates in positioning, support or coordination according to the specific structure.
The insert plate assemblies of different mud pump models may vary in shape, the number of copper blocks, positioning slots, hole positions and installation dimensions. Therefore, a certain F series structure cannot be directly applied to all mud pumps.
For structures that use copper blocks or other replaceable mating parts, during procurement and maintenance, the dimensions and assembly relationship between the main body of the plug-in plate and the matching blocks should be confirmed simultaneously. It is not advisable to replace only one part while neglecting the overall fit.
The fit relationship with the lower valve stem guide
There is a direct positioning and support relationship between the insert plate assembly and the lower valve stem guide. The lower valve stem guide is responsible for guiding the movement of the valve stem, while the plug plate assembly is responsible for keeping the guide at the position specified in the design.
If the positioning surface of the insert plate assembly is worn, the copper block is worn or the installation clearance is abnormal, the lower valve stem guide may become loose or shift in position, which will affect the movement axis of the valve stem and increase the possibility of valve body wobble and abnormal wear of the valve seat.
Therefore, when abnormal loosening of the lower valve stem guide is found, in addition to checking the guide itself, the positioning groove, support surface and matching blocks of the insert plate assembly should also be inspected simultaneously.
The working relationship in the valve group
When the mud pump valve assembly is in operation, the valve body opens under the action of pressure difference, the valve spring is compressed, and the valve stem moves in the specified direction under the constraint of the guide vane.
Although the plug plate assembly does not directly seal the valve body nor directly provide the return force, it indirectly ensures that the valve group has a stable motion guiding foundation by fixing the lower valve stem guide.
This is also the main functional difference between the insert plate assembly and the valve spring, valve stem guide and valve body: the insert plate assembly is responsible for positioning and support, the valve stem guide is responsible for movement guidance, the valve spring is responsible for returning to position, and the valve body and valve seat are responsible for opening and closing as well as sealing.
Main mating dimensions
When selecting the plug-in plate assembly, particular attention should be paid to its fit dimensions with the liquid cylinder and the lower valve stem guide, including the external dimensions of the plug-in plate, the total thickness, the width of the positioning groove, the positioning step, the size of the copper block, and the geometric relationship with the contact position with the guide.
Some structures may be equipped with installation holes, limit slots, openings or special profiles, which are usually matched with the internal space of the liquid cylinder and the assembly direction of the valve group. Even if the external dimensions of the two plug-in plate assemblies are close, they cannot be directly interchanged as long as the mating dimensions of the positioning slots or guides are different.
Common wear and tear and faults
The plug plate assembly is constantly inside the hydraulic end of the mud pump and may be subject to the combined effects of mechanical vibration, repeated shock, drilling fluid erosion, and the load transmitted by the guide vane.
Common abnormalities include wear on the positioning surface of the insert plate, expansion of the positioning groove, wear of the copper block, increase in fit clearance, local indentations, corrosion, deformation and cracks.
If the matching copper block undergoes obvious wear, it may cause the lower valve stem guide to lose its stable support. If the main body of the guide plate is deformed or the positioning groove is damaged, it may also cause the installation position of the guide to shift.
When conducting maintenance, it is not only necessary to check whether the plug plate is broken, but also to inspect the dimensions of its positioning surface, the fit clearance, and the condition of the copper blocks and other matching parts.
The difference from the positioning disk
Insert plate assembly: Installed inside the cylinder in a typical F series mud pump, it is mainly used to fix and correct the lower valve stem guide and may consist of multiple parts such as insert plates and copper blocks.
Positioning disc: Generally, it belongs to an independent disc-type positioning part, mainly establishing assembly positions through center holes, outer circles or steps.
Both have positioning functions, but their structures, installation positions and matching objects are different. They cannot be substituted for each other just because they both belong to positioning parts.
Key points for selection
When purchasing the drilling mud pump insert plate assembly, 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. Part number of the original board insertion assembly;
4. Model of the matching lower valve stem guide;
5. External dimensions of the main body of the plug-in board;
6. Total length, width and thickness of the plug-in board;
7. Positioning slot width, depth and position;
8. Dimensions of positioning steps and support surfaces;
9. Quantity and size of copper blocks or matching blocks;
10. Installation relationship between copper blocks and insert plates;
11. Installation holes, limit slots or other special structures;
12. The fit dimensions between the insertion plate assembly and the internal installation position of the liquid cylinder;
13. Material and heat treatment requirements;
14. Physical samples or technical drawings.
Installation and Inspection
Before disassembling and assembling the plug plate assembly, it is necessary to confirm that the mud pump has been shut down, and the hydraulic end and high-pressure discharge system have been completely depressified. Then, remove the relevant cylinder heads, plugs or positioning parts in accordance with the corresponding mud pump maintenance procedures.
Before installation, the plug plate assembly, the internal positioning position of the liquid cylinder and the lower valve stem guide should be cleaned. Remove mud, sand particles, rust and metal shavings, and check whether there are burrs or severe indentations on the positioning surface.
For the insert plate assembly with copper blocks, it is necessary to check whether the copper blocks are installed properly, whether there is obvious wear, looseness or missing, and confirm that the fit relationship with the lower valve stem guide is correct.
After the plug plate assembly is installed, it should be confirmed that the lower valve stem guide can be correctly positioned, and there should be no abnormal loosening or obvious deviation. Do not install mismatched board assemblies by forcibly knocking or modifying the positioning slots.
Procurement Instructions
Juli Petroleum Drilling and Production Equipment Co., Ltd. provides insert plate assemblies and hydraulic end valve group accessories for drilling mud pumps. The plug plate assembly is mainly used for the alignment, positioning and fixation of the lower valve stem guide inside the liquid cylinder. It can be selected according to the model of the mud pump, the model of the liquid cylinder, the model of the lower valve stem guide, the size of the plug plate, the positioning groove, the structure of the copper block, the original part number and the technical drawing.