Sanitary Positive Displacement Flow Meter

What is a flow meter that uses sanitary positive displacement?

A sanitary positive displacement flow meter is a flow meter made just for sanitary or hygienic uses, like the food and drink industry, the pharmaceutical industry, or the biotechnology industry. It is used to measure the flow rate of liquids, usually in processes where cleanliness and hygiene are very important, like with high fructose corn syrup (HFCS), a milk flow meter, a honey flow meter, a molasses flow meter, an edible oil flow meter, a water flow meter, a cooked vegetable oil flow meter, a palm oil flow meter, a sunflower oil flow meter, etc.
Liquid turbine flow meters and electromagnetic flow meters can't measure high viscosity liquids like honey and molasses. Positive displacement flow meters can measure these kinds of liquids. PD flow meters are also much cheaper than Coriolis mass flow meters, which makes them more affordable for a lot of customers.

How does a PD flow meter work?

The way positive displacement flow meters work is by trapping and measuring separate amounts of fluid to measure the flow of fluid. There is a chamber or cavity that fills and empties as the fluid flows through the meter. To find the flow rate, you then use this fluid movement. An oval gear flow meter is a common type of positive displacement flow meter.
How do positive displacement flow meters meet the need for cleanliness and health?
A sanitary PD flow sensor is made with stainless steel materials and special construction that make sure it meets the strict sanitary standards of the industries it works in. These PD flow sensors are usually made of high-quality stainless steel 304, 316, or 316L, and their surfaces are smooth and polished to keep bacteria and other contaminants from building up.
Hygienic flow sensors often have features like CIP (Clean-in-Place) and SIP (Sterilize-in-Place), which make it easy for factory to clean and sterilize the flow sensors them without taking them apart from the pipelines. To make sure that installation and maintenance are clean and sanitary, they may also have sanitary fittings and connections, like tri-clamp ,tr-clover or  thread process connections.

Technical specifications for a sanitary positive displacement flow meter

Different principle of positive displacement flow meters may have different technical technical specifications. Still, here are some common technical specifications you might see for positive displacement flow meters:

• Positive displacement flow meters come with a variety of sensor sizes and are widely used. There are sanitary PD flow meters that are 1/2" (15mm), 1 inch (25mm), 3/4 inch (20mm), 2"(DN50), 2.5", 3", or DN80, 4", or DN100mm.
• Flow Range: Most sanitary positive displacement flow meters can measure a wide range of flow rates, from very low to very high. For example, a 3/4" PD flow meter can measure 300–3000 LPH, a 1" sanitary oval gear flow meter can measure 0.6–6 m3/h, and a 2 inch PD flow meter can measure liquid 10–100 GPM.
• Accuracy: Positive displacement flow meters are known for being very accurate when it comes to measuring flow rates. Usually, the accuracy is shown as a percentage of the full-scale reading or the measured value. For instance, an accuracy of ±0.5% of the reading or ±0.2% of the full scale.
• Repeatability: This is the flow meter's ability to give the same readings for the same flow conditions over and over again. Similar to accuracy, it is usually given as a percentage of the measured value or the full-scale reading.
• Pressure Rating: Sanitary Positive displacement flow meters can handle pressure ranges of up to 10 bar. This is because a tri-clamp or tri-clover PD flow meter can only handle a pressure range of 1Mpa.
• The temperature range tells you the lowest and highest temperatures at which the sanitary PD flow meter can work well. To make sure the flow meter can handle the temperature of the fluid being measured, it is important to think about the temperature range. The PD flow meter can handle up to 150°C.
• Viscosity Range: Positive displacement flow meters can measure fluids with a wide range of viscosities. The viscosity range specification tells you the lowest and highest viscosities at which the flow meter can give you accurate readings. It is often measured in centipoise (cP) or centistokes (cSt). The hygienic helical gear flow meter can measure liquid with max viscosity range of up to 2000 mPa.s.
• Output Signal: Sanitary PD flow transmitters can be mechanical register or they can send flow data to control systems like PLC, DCS or flow computers in different ways. Digital communication protocols like Modbus RTU or HART, pulse outputs, and analog signals (4–20mA current) are all common output signals from positive displacement flow transmitter.

The end

Factories often use sanitary positive displacement flow meters when they need to measure different kind of liquid flow very accurately also has hygienic demand , like when they are dosing ingredients, keeping track the flow of process liquids, or controlling the flow rate during production. They measure flow accurately and dependably while still keeping the sanitary standards that the industry needs.

It's important to know that there are different kinds of positive displacement flow meters. For example, there are roots flow meters, oval gear meters, gear flow meter, and helical gear flow meter. The design of each one may be different depending on the manufacturer and the needs of the application.

Send us an email or leave a message.