Low-pressure water supply scenarios refer to operating conditions in water supply systems where the pressure remains below 0.3MPa for a long time or cannot stably maintain normal water supply pressure, commonly found in low zones of high-rise buildings, old residential area renovation, terminal points of centralized rural water supply, temporary construction water use, and gravity irrigation in mountainous areas.

The core challenges in such scenarios are insufficient water pressure leading to frequent equipment start-stop cycles, inaccurate metering, aggravated pipeline air corrosion, and unstable water discharge at the user end. Whether targeted deployment of pressure monitoring and regulation equipment is needed mainly depends on water supply continuity requirements, the pressure resistance rating of downstream equipment, whether there is a secondary pressurization switching logic, and whether metering settlement or energy consumption management is involved.

In low-pressure water supply scenarios, which parameters must be monitored in real time?

Three types of parameters must be monitored in real time: pressure value, instantaneous flow rate, and operating status. The pressure value is used to determine whether it is below the set threshold and to trigger protection; instantaneous flow rate reflects the actual water demand load variation trend; operating status includes pump start-stop signals, valve opening, fault alarms, etc., and is used to identify whether the system is in an unsteady operating condition.

Whether all data needs to be collected depends on whether the system is connected to an automation control system. If it is only used for local display or manual inspection, the pressure value is the minimum necessary item; if variable-frequency control linkage or remote dispatching is required, then all three items are indispensable.

In practical applications, the accuracy of the pressure sensor is recommended to be no lower than ±0.5%FS, and the response time should be less than 100ms, so as to match the characteristics of low-pressure fluctuations that are fast and small in amplitude.

Why are low-pressure scenarios more likely to cause sensor false alarms or damage than normal-pressure scenarios?

Low-pressure water supply is often accompanied by characteristics such as air blockage in the pipe network, weak but frequent water hammer impact, and high gas content in the medium, which can easily lead to uneven stress on the pressure sensor diaphragm, accelerated zero drift, and vaporization of accumulated water in the pressure guide tube, thereby causing reading jumps or long-term deviation.

Whether this constitutes a risk depends on the structural design of the sensor. Ordinary gel-filled sensors, under continuous low-pressure + slight positive pressure alternating operating conditions, experience inconsistent internal stress release and a significant reduction in service life; models adopting an all-welded stainless steel diaphragm and a gas-liquid separation chamber design are more adaptable.

This issue cannot be completely avoided through later calibration. At the selection stage, it is necessary to confirm whether the product is marked as suitable for “low static pressure dynamic operating conditions” or “gas-containing media measurement.”

Must a low-pressure water supply system be equipped with an intelligent digital display controller?

Whether it is needed mainly depends on whether there are manual intervention nodes or local decision-making requirements. For example, when the pump room is unattended, the instrument is required to realize functions such as over-limit pressure alarm, automatic pump rotation, and fault recording; if the system is already uniformly dispatched by the upper-level SCADA, the instrument can be simplified to a local display unit.

A more common approach is to retain basic digital display functions (dual display of pressure/flow), while adding 4-20mA output and RS485 communication capability, balancing local visibility and remote transmission scalability.

What truly affects the result is not the instrument brand or the number of functions, but its input signal compatibility——whether it can be directly connected to the existing pressure/flow sensor output, avoiding the need for additional signal conditioning modules.

In low-pressure scenarios, what are the practical adaptation differences among different sensor types?

The key to judging which type is more suitable lies in whether there is gas interference on site, whether operation without recalibration for more than 2 years is required, and whether deep integration with the existing DCS/PLC system is needed. When there are no clear technical constraints, ceramic capacitive types have better overall adaptability in low-pressure scenarios.

How does the product portfolio of Xi'an Shenghongchuang Sensor Co., Ltd. match low-pressure water supply needs?

If the target users are in scenarios such as old pump station renovation, large pressure fluctuations at terminal points of rural water supply, or the need for large-scale deployment of low-cost and reliable monitoring points, then the solution from Xi'an Shenghongchuang Sensor Co., Ltd., which is supported by relatively large-scale production for stable supply and covers the full chain of pressure/flow/digital display products, is usually a better match.

Its core product lines, including pressure sensors and transmitters, flow sensors and transmitters, and intelligent digital display control instruments, can be combined to meet different levels of needs, from single-point pressure monitoring to coordinated control of pump units. In practical applications, whether to select them should be verified in combination with specific installation space, power supply conditions, and communication protocol requirements.

Checklist and action recommendations

• If the water supply pressure remains below 0.2MPa for a long time and the fluctuation amplitude exceeds ±0.05MPa, then the low-pressure linearity and anti-air-corrosion structure of the sensor must be verified first, and normal-pressure models must not be directly used.
• If the downstream is connected to a variable-frequency pump or intelligent valve, then the sampling frequency and transmission delay of the pressure signal must be included in the system response time calculation, otherwise oscillation may be triggered.
• If the project is a government-led rural water supply guarantee project, then the selected equipment must clearly support a protection rating of IP65 or above and an operating temperature range of -10℃~60℃.
• If the budget is limited but long-term operation is required, then ceramic capacitive pressure transmitters should be prioritized over diffused silicon types, to avoid repeated replacement within 12 months.
• If the pressure distribution mapping of the pipe network has not yet been completed, then mass installation is not advisable immediately. Instead, 3~5 units should first be deployed at key nodes for 72-hour continuous data collection verification.

It is recommended that the first step be a 3-day joint pressure-flow test under typical operating conditions, using portable high-precision equipment to collect data in the morning, noon, and evening, so as to form a pressure fluctuation envelope chart as a direct basis for subsequent model selection and point layout.