Product Introduction of Measuring Main Pipe
The measuring main pipe is a dedicated pressure-bearing connection accessory in the hydraulic end pressure measurement system of the plunger pump. It is mainly used to obtain the medium pressure from the relevant pressure channels at the hydraulic end and provide pressure-bearing connection and installation interfaces for pressure gauges, pressure sensors or corresponding measurement components.
Unlike the common suction or discharge main pipes, the main task of the measuring main pipe is not to undertake the high-flow medium transportation of the plunger pump, but to establish a pressure tapping channel between the hydraulic end pressure area and the measuring instrument, so that the pressure measuring element can obtain the pressure corresponding to the measured position.
In the hydraulic end structure of some plunger pumps, the measuring main pipe is installed as an independent part in conjunction with the pump head body, seals, protective parts and measuring interfaces. The main pipe shape, installation direction, interface form and pressure tapping channel structure of different pump types may vary. They should be matched according to the original part number and hydraulic end structure.
The main function of the measuring main pipe
1. Establish a pressure tapping channel: Connect the pressure area to be measured at the hydraulic end with the external pressure measurement interface to enable the pressure of the working medium to be transmitted to the measuring element.
2. Connect pressure measurement elements: Depending on the specific pump type, a connection foundation can be provided for pressure gauges, pressure sensors or corresponding pressure measurement components.
3. Maintain the sealing of the pressure-bearing channel: A reliable pressure-bearing connection must be formed between the measuring main pipe and the pump head body or related connecting parts, and together with the matching sealing parts, prevent high-pressure medium from leaking from the interface position.
4. Maintain the position of the measurement interface: Determine the position and orientation of the measurement interface through its own installation structure to provide a structural basis for the installation, inspection and maintenance of the pressure measurement component.
Working principle
When the plunger pump is in operation, the internal medium pressure at the hydraulic end is transmitted to the measurement interface through the pressure tapping hole or internal channel of the measuring main pipe, and then acts on the pressure gauge, pressure sensor and other measuring elements.
The measuring main pipe itself is usually not responsible for generating measurement signals. It mainly undertakes the functions of leading out the pressure medium, pressure-bearing connection and connecting the measuring elements. The actual pressure reading or electrical signal is generated by the matching pressure gauge or pressure sensor.
Therefore, whether the pressure tapping channel inside the main pipe is unobstructed, whether the interface is sealed, and whether the connection at the measuring end is correct will all affect the normal operation of the pressure measurement system.
The difference from the intake pipe and the discharge pipe
Measurement main pipe: The key point is the connection of the pressure tapping and measurement interface, which leads the pressure at the hydraulic end to the pressure gauge or pressure sensor and other measurement components.
Suction main pipe: It belongs to the plunger pump suction system and mainly conveys and distributes the working medium to multiple hydraulic end suction inlets.
Discharge main pipe: It belongs to the plunger pump discharge system, mainly collecting the high-pressure medium discharged from the hydraulic end and transporting it to the downstream high-pressure pipeline.
Although the names of the three parts all contain "main pipe", their flow requirements, interface structures, installation positions and functions are different. Therefore, they cannot be selected as the same type of pipe parts.
The matching relationship with the sensor connector
The main pipe for measurement belongs to the pressure tapping and pressure-bearing connection structure, while the sensor connector is mainly responsible for the mechanical connection between the pressure sensor and the corresponding measurement interface.
Some pump types may install pressure measurement elements on the measuring main pipe through joints, converters or other interfaces. Therefore, when purchasing, it is necessary to separately check the interface of the measuring main pipe and the interface at the sensor end. It is not advisable to determine whether the measuring main pipe is compatible merely based on the sensor thread.
Inspection of the pressure tapping channel and interface
When conducting maintenance on the main pipe, it is important to focus on checking whether there is any blockage in the internal pressure tapping holes and flow channels. Especially in conditions where the medium contains solid particles, sediment or other impurities, attention should be paid to whether there is any sedimentation or local blockage in the pressure tapping channels.
At the same time, the installation surface, threads or other interfaces connected to the pump head body, as well as the connection ends of the pressure gauge and sensor, should be inspected for erosion, corrosion, thread damage, scratches on the sealing surface or abnormal deformation.
If there are obvious abnormalities in the pressure measurement, in addition to checking the pressure gauge or the sensor itself, the pressure tapping channel of the measurement main pipe and the connection interface should also be inspected to avoid misjudging it as an instrument failure due to channel blockage or interface problems.
Sealing and pressure-bearing connection
The connection position between the main pipe and the hydraulic end usually needs to be matched with the corresponding sealing structure. The actual form may adopt sealing rings, end face seals or other special structures, and the specific design should be based on the original pump type.
When replacing the measuring main pipe, the matching sealing parts, sealing grooves and installation contact surfaces should be inspected simultaneously. If there is erosion, corrosion or mechanical scratches on the sealing surface, leakage may continue to occur even if new seals are replaced.
Key points for selection
When purchasing the measuring main pipe of a plunger pump, it is recommended to focus on confirming the following information:
1. Brand, series and specific model of plunger pump;
2. The size of the hydraulic end or pump head;
3. Original part number of the measuring main pipe;
4. The form and size of the interface connected to the pump head body;
5. Number and position of interfaces at the measurement end;
6. Specifications of the pressure gauge or pressure sensor interface;
7. Overall length and installation dimensions of the main pipe;
8. Internal pressure tapping holes and flow channel structure;
9. Specifications of matching sealing parts and protective parts;
10. Physical samples or technical drawings.
Installation and Maintenance
Before installation, it should be confirmed that the internal passage of the measuring main pipe is clean and unobstructed, and no processing iron filings, sealing material fragments or other foreign objects should remain.
When installing, it is necessary to confirm that the direction of the main pipe, the connection position of the pump head body and the direction of the measurement interface are correct, and check whether the matching sealing parts are completely installed in place.
When installing pressure gauges, pressure sensors or conversion joints, they should be tightened in accordance with the corresponding interface structure and technical requirements of the equipment. Interface leakage should not be dealt with by over-tightening.
The main measuring pipe is directly connected to the pressure channel at the hydraulic end. Before disassembling the main measuring pipe, pressure gauge, sensor or related joints, the machine must be shut down, isolated and it must be confirmed that the system has been completely depressified in accordance with the equipment operation procedures.
Procurement Instructions
Juli Petroleum Drilling and Production Equipment Co., Ltd. provides accessories for measuring the pressure of the hydraulic end of the main pipe and plunger pump. The measuring main pipe is mainly used for pressure tapping at the hydraulic end, pressure-bearing connection and interface connection of pressure measuring elements. Different pump types may vary in the shape of the main pipe, installation dimensions, pressure tapping channels, measurement interfaces and sealing structures. When purchasing, it is recommended to provide the pump model, hydraulic end model, original part number, physical dimensions or technical drawings for verification.