Description
Plastic Threaded Rotameter for Water – 3000 to 15000 LPH
The Plastic Threaded Rotameter for Water, Range 3000 to 15000 LPH is a practical, economical, and reliable variable-area flow measurement instrument designed for continuous local monitoring of water flow in industrial, commercial, process, utility, and water-treatment applications. With a wide flow measurement range of 3000 to 15000 Litres Per Hour (LPH), this model is suitable for higher-capacity water-flow systems where simple, direct, and easy-to-read flow indication is required.
Designed specifically for water with a specific gravity of 1, this plastic threaded rotameter features a transparent polycarbonate body, SS 316L float, and ABS end material. The transparent measuring section allows operators to visually observe the float position during operation, providing immediate information about the current flow condition without requiring an external electrical display.
The instrument is equipped with 2″ BSP (M) threaded connections at both the top and bottom, making it suitable for inline installation in compatible piping systems. The standard flow configuration is bottom inlet and top outlet, allowing water to move upward through the measuring section and enabling the float to respond to changes in flow rate.
The rotameter operates according to the proven variable-area flow measurement principle. As water enters through the bottom connection, the flow causes the float to rise within the measuring section. When flow increases, the float moves upward; when flow decreases, it moves downward. Once the flow stabilizes, the float reaches a position corresponding to the water-flow rate, which can be read against the graduated scale.
With a specified accuracy of 2% of full scale, maximum operating temperature of 60°C, and maximum operating pressure of 5 kg/cm², this rotameter provides a convenient and economical solution for general-purpose water-flow monitoring within its specified operating conditions.
Variable-Area Flow Measurement Principle
The Plastic Threaded Rotameter uses the well-established variable-area principle for measuring fluid flow.
Water enters the instrument from the bottom and flows upward through the measuring passage. The upward force generated by the flowing water causes the float to rise. The float position changes according to the amount of water flowing through the instrument.
At a stable flow condition, the float settles at a corresponding position on the scale. The operator can observe the float through the transparent polycarbonate body and determine the approximate flow rate.
The simple mechanical operating principle provides several benefits:
- Direct visual flow indication
- Continuous local monitoring
- No external power required for basic indication
- Simple operation
- Easy inspection
- Low-maintenance design
- Economical flow measurement
- Convenient troubleshooting
This makes the instrument suitable for applications where a straightforward local flow indication is preferred over complex electronic flow-measuring equipment.
3000 to 15000 LPH Flow Range
The specified water-flow range of this model is:
3000 to 15000 LPH
This higher flow range makes the rotameter suitable for larger-capacity water circuits and industrial utility applications.
It can be considered for applications such as:
- Water treatment plants
- RO and water purification systems
- Industrial cooling-water systems
- Filtration systems
- Process-water circulation
- Utility-water lines
- Industrial machinery
- Water circulation equipment
- Industrial washing systems
- Process equipment
- General industrial water-flow monitoring
The rotameter should be selected according to the actual process requirements and operated within the specified temperature and pressure limits.
Transparent Polycarbonate Body
The measuring body is manufactured from polycarbonate, providing a transparent section for direct observation of the float.
One of the key benefits of the transparent body is that the operator can see the float position while the process is running. This makes it easier to identify changes in flow without depending on an electronic display or external measuring device.
The transparent body can assist with:
- Confirming water flow
- Observing flow variations
- Monitoring float movement
- Identifying unstable flow
- Detecting significant flow reduction
- Performing routine visual inspection
The polycarbonate construction also contributes to the lightweight and economical design of the rotameter.
The instrument should always be used within its specified maximum operating temperature and pressure.
SS 316L Float
The rotameter is equipped with an SS 316L float, which acts as the primary moving measurement element.
The float moves vertically according to the flow conditions inside the measuring section. Increasing water flow causes the float to rise, while decreasing flow causes it to move downward.
SS 316L is commonly used in industrial instrumentation because of its corrosion-resistant characteristics and suitability for many compatible water and process applications.
The stainless-steel float provides a durable and clearly visible measuring element for routine flow monitoring.
2″ BSP (M) Threaded Connections
This model is supplied with:
2″ BSP (M) connections at the top and bottom
These threaded connections allow inline installation into compatible piping systems.
The standard flow arrangement is:
Bottom Inlet → Measuring Section → Top Outlet
Correct installation orientation is important because the float is designed to move vertically under the combined effects of fluid flow and gravity.
Before installation, the piping system and associated fittings should be checked for compatibility with the 2″ BSP male connections.
Designed for Water – Specific Gravity 1
This rotameter is specified for:
Water – Specific Gravity 1
The flow scale is intended for water with the specified density characteristics. If the instrument is used with a different liquid having substantially different density or viscosity, the float position may not correspond directly to the indicated water-flow value.
Therefore, this product should be used for its intended water application unless suitable correction factors or application-specific calibration are available.
Maximum Operating Temperature – 60°C
The maximum specified operating temperature is:
60°C
This makes the instrument suitable for many standard and moderately warm water-flow applications.
The actual process temperature should be checked before installation. The specified maximum operating temperature should not be exceeded during operation.
Maximum Operating Pressure – 5 kg/cm²
The maximum specified operating pressure is:
5 kg/cm²
The rotameter should be installed in systems where the operating pressure remains within this limit.
Pressure fluctuations and sudden pressure surges should also be considered during system design and installation.
The connected piping should be properly aligned and supported to reduce mechanical stress on the rotameter and threaded connections.
Accuracy – 2% of Full Scale
The specified accuracy of this rotameter is:
2% of Full Scale
This accuracy is suitable for many general-purpose industrial water-flow monitoring applications.
The instrument can be used where operators need to continuously observe flow and verify that water circulation remains within the desired operating range.
For applications requiring high-precision or certified flow measurement, the specified accuracy should be evaluated against the individual application requirements.
Tamper-Proof Scale Sticker
The instrument is supplied with a tamper-proof scale sticker for convenient flow indication.
The scale graduation is:
LPH / LPM
The operator can observe the float position through the transparent body and compare it with the corresponding graduation on the scale.
For consistent readings, it is recommended to allow the water flow to stabilize before recording the indicated value.
Dimensions
The approximate dimensions of this model are:
400 mm Height × 120 mm Width
The measuring body is designed for the specified higher flow range of 3000–15000 LPH.
Adequate space should be provided around the instrument during installation so that operators can easily view the float and scale and perform routine inspection.
Industrial Applications
1. Water Treatment Plants
The rotameter can be used for local monitoring of water flow through compatible treatment, filtration, and circulation equipment.
2. RO and Water Purification Systems
It can provide visual flow indication in suitable reverse-osmosis and water-purification systems.
3. Cooling-Water Systems
The instrument can be used to monitor compatible industrial cooling-water circuits where maintaining adequate water flow is important for equipment operation.
4. Filtration Systems
The rotameter can be installed on suitable filtration systems to provide continuous local indication of water flow.
5. Process-Water Applications
Its 3000–15000 LPH range makes it suitable for higher-flow process-water circuits.
6. Industrial Utility Systems
The instrument can provide simple local monitoring in compatible industrial utility-water lines.
7. Industrial Machinery
It may be used for compatible water-based cooling, cleaning, circulation, and process applications.
Benefits of This Plastic Threaded Rotameter
1. Simple and Easy to Operate
The rotameter provides direct visual flow indication without complicated programming or electronic configuration.
2. Continuous Monitoring
Operators can observe the float position continuously while the water system is operating.
3. Economical Instrumentation
The mechanical design provides an economical option for applications where basic local flow measurement is sufficient.
4. Easy Inline Installation
The 2″ BSP (M) connections at the top and bottom allow convenient installation into compatible piping systems.
5. Low Maintenance
The simple mechanical construction helps keep routine inspection and maintenance straightforward.
6. Suitable for Higher Flow Rates
The 3000–15000 LPH measuring range makes this model suitable for higher-capacity water-flow applications.
Installation Guidelines
For correct operation, the rotameter should be installed vertically, with the water inlet at the bottom and outlet at the top.
Before commissioning:
- Confirm compatibility with the 2″ BSP (M) threaded connections.
- Install the instrument vertically.
- Maintain the specified bottom-to-top flow direction.
- Keep the operating flow within 3000–15000 LPH.
- Ensure operating pressure remains below 5 kg/cm².
- Ensure water temperature remains below 60°C.
- Properly align and support the connected piping.
- Ensure the float is free to move within the measuring section.
- Avoid excessive vibration and sudden pressure surges.
- Allow the water flow to stabilize before taking a reading.
Maintenance
The rotameter has a simple mechanical construction, making routine inspection relatively straightforward. Periodically inspect the polycarbonate body, SS 316L float, scale, threaded connections, and general condition of the instrument.
If dirt, deposits, or contaminants interfere with float movement, the instrument should be safely isolated from process pressure and flow before cleaning or servicing.
Regular inspection can help identify abnormal float movement, deposits, physical damage, or connection-related issues and help maintain dependable flow indication.
Conclusion
The Plastic Threaded Rotameter for Water – 3000 to 15000 LPH is a practical and economical solution for continuous local monitoring of higher water-flow rates. Its variable-area measurement principle, transparent polycarbonate body, SS 316L float, ABS end construction, tamper-proof LPH/LPM scale, and 2″ BSP (M) threaded connections provide a straightforward method for visual flow indication.
With a 3000–15000 LPH flow range, 2% full-scale accuracy, maximum operating temperature of 60°C, and maximum operating pressure of 5 kg/cm², this model is suitable for compatible water-treatment, RO, cooling-water, filtration, process, and industrial utility applications.
For industries and equipment manufacturers looking for a simple, visible, economical, and low-maintenance water-flow monitoring solution, this Plastic Threaded Rotameter provides an effective option for higher-capacity water-flow applications.
Japsin Instrumentation – Since 1974

Eesha Choudhury –
Very reliable
Bhavya Khurana –
Reliable performance, perfect fit!
Tanishka Choudhury –
Nice Product