Equipment such as energy storage units, data centers, and wind power converters often utilize multi-channel parallel liquid cooling pipelines, with multiple branches providing simultaneous heat dissipation. Any blockage, imbalance in flow, or liquid leakage in any branch can lead to overall failure in heat dissipation. Pure single-point pressure monitoring makes it difficult to diagnose faults in individual branches. By utilizing the Longlv PTL537 digital display differential pressure switch for differential pressure measurement point layout, it is possible to simultaneously monitor the pressure of the main pipeline and the flow status of each branch, quickly locate abnormal branches, and adapt to centralized management and control of parallel liquid cooling systems.

1. Core requirements for monitoring multi-channel parallel liquid cooling pipelines

    Monitor the pressure of the main pipeline in real time to ensure stable overall circulating pressure, and predict main pump failures and blockages in the main pipeline;

    Each parallel branch is independently monitored to quickly distinguish between single-branch blockage, medium leakage, and insufficient flow;

    For branch filter elements and plate heat exchangers, implement differential pressure early warning systems and arrange for cleaning and maintenance in advance;

    Local visual reading + remote signal upload, automatic alarm interlock for pressure anomalies, suitable for unattended machine rooms.

A standard single pressure transmitter can only read single-point static pressure and cannot determine the degree of pipeline patency. However, the PTL537 differential pressure device can collect pressure differences between two points, intuitively reflecting the flow resistance in the pipeline, making it more suitable for parallel multi-channel pipeline layouts.

II. Hierarchical arrangement of Level 2 and Level 3 measurement points (main pipe + branch + filtering unit)

1. Main loop header pipe measuring point (system main control point)

A PTL537 is arranged on the main pipeline at the outlet of the circulating pump, with one end connected to the high pressure at the pump outlet and the other end connected to the low pressure at the system's return water main, to monitor the total pressure difference of the entire parallel system.

Function: It is used to judge the output attenuation of the main pump, the scaling of the main pipeline, and the overall flow reduction. If the total pressure difference continues to increase, it indicates that there is a large-scale blockage in the overall pipeline. When combined with a relay switch, the overpressure/underpressure of the main pipeline directly triggers the start/stop of the main pump and the opening of the pressure relief valve, providing primary pressure protection for the entire machine.

2. Independent differential pressure measuring points for each parallel branch (core branch monitoring)

All parallel branches adopt a unified measuring point layout logic, with pressure taps introduced at the inlet and outlet of each single branch, which are respectively connected to two pressure interfaces of the same PTL537.

Each branch is equipped with a digital differential pressure switch, and the local screen directly displays the pressure difference value of that branch.

    Normal pressure difference: The branch is flowing smoothly and the flow rate meets the standard;

    The pressure difference is significantly high: there is sedimentation of impurities in the cold plate and pipeline inside the branch;

    The pressure difference is low and close to zero: there is leakage in the branch or the valve is not fully opened.

    During operation and maintenance inspections, by comparing the displayed values of multiple PTL537 channels, branches with abnormal pressure differences can be directly identified, eliminating the need to dismantle and inspect each channel individually, thereby significantly reducing maintenance time.

3. Differential pressure measuring points before and after the branch filter (pre-warning points)

The front-end filter of each branch is a high-risk location for impurity accumulation. Pressure is introduced at the inlet and outlet of the filter, and a PTL537 is installed for real-time monitoring of the pressure difference across the filter element.

When the pressure difference reaches the set threshold, the device will output an alarm through its built-in switch to provide an early warning for replacing the filter element, thus preventing impurities from entering the cold plate and causing blockage in the branch circuit, thereby reducing the probability of parallel pipeline failures at the source.

III. The outstanding advantages of Longlv PTL537 in adapting to parallel liquid cooling multi-channel layout

    A device synchronously collects pressure data from two points, simplifying pipeline tapping

    There is no need to install two transmitters at both ends of the branch. A single PTL537 with dual pressure taps can complete the pressure difference measurement, reducing the number of openings in parallel pipelines, lowering the risk of coolant leakage, and making installation simpler in scenarios with multiple closely arranged branches.

    Equipped with on-site digital display, multi-channel comparison and troubleshooting, it offers high efficiency

    Each branch instrument independently displays the pressure difference. Operation and maintenance personnel can conduct inspections along the parallel pipelines, visually compare the values of each branch, and quickly identify the channels with abnormal pressure differences. The buttons on the device allow for on-site independent setting of the alarm threshold for each branch, adapting to different branch flow design requirements.

    The flat anti-blocking structure is compatible with liquid cooling medium

    The contact medium part is free from small pressure-inducing cavities, and the trace precipitates and impurities in the cooling liquid are not prone to accumulate and block the holes. Under long-term uninterrupted circulation conditions with multiple branches, the pressure difference measurement remains stable, without numerical drift or false alarms.

    Transmitting + switching dual signals to achieve hierarchical interlocking protection

    The 4-20mA signal is connected to the PLC to centrally collect differential pressure data from all branches and draw pressure operation curves. The relay contacts can be independently set for differential pressure alarms, and a single branch blockage will trigger an audible and visual alarm independently, without affecting the normal operation of other parallel branches. The system implements early warning and shutdown protection logic in stages.

    Anti-vibration and high protection, suitable for dense parallel pipelines in cabinets

    The entire machine is sealed to prevent moisture and dust, ensuring stable operation in low-temperature condensation environments in the machine room. The internal reinforced structure can withstand continuous vibration from the circulating pump, and multiple instruments working simultaneously will not cause signal interference, resulting in good measurement consistency.

IV. Simplified layout schemes for different parallel connection scales

    Small multi-branch (3-6 parallel branches, charging pile, converter water cooling)

    One PTL537 main unit + one filter for each branch, balancing overall pressure and filter element early warning, with moderate cost, meeting basic monitoring needs.

    Medium-sized multi-branch (8-16 branches in parallel, liquid cooling for energy storage battery clusters)

    One main controller + each branch independently equipped with PTL537, simultaneously monitoring the pressure difference of the branch and the pressure difference of the filter element, accurately locating single-channel cold plate blockage and liquid leakage faults.

    Large-scale multi-channel parallel (more than 20 channels, liquid cooling for data center cabinets)

    The main system is equipped with total pressure difference monitoring and standard branch filters, while key core branches are additionally equipped with branch inlet and outlet pressure difference measurement points, balancing operational and maintenance costs with equipment safety.

V. Practical considerations for the layout of measuring points

    All pressure taps of the parallel pipeline are uniformly arranged above the horizontal section of the pipeline to avoid bubbles and impurities in the pipeline accumulating at the pressure taps, which may affect the accuracy of pressure difference measurement;

    The lengths of the two pressure pipelines should be kept as consistent as possible to reduce pressure difference errors caused by medium transmission delays;

    Multiple PTL537 devices are calibrated synchronously to ensure a unified zero point, guaranteeing consistent pressure difference benchmarks across all branches and more accurate numerical comparisons;

    The instrument wiring port should be installed facing downwards to prevent condensed water vapor from infiltrating into the meter head and prolong its service life.