The Hedland flow meters type H for aggressive environment are nearly identical to high pressure variable area flow meters. The most important difference is the material, which was used to produce the flow meters, that does not react with measured medium and external aggressive environment. The flow meters provide direct reading of flow rate in difficult external conditions.

Flow measurement: from 0.5 through 380 lpm; maximum pressure: up to 414 bar.

The Hedland flow meter is a variable area instrument. A precision machined, sharp-edged orifice located within the piston assembly, forms an annular opening with the contoured metering cone. The piston assembly carries a cylindrical magnet that is magnetically coupled to an external flow indicator that moves precisely, in direct response to movement of the piston. A calibrated spring opposes flow in the forward direction. This spring decreases viscosity sensitivity and allows the flow meter to be used in any position.

The Hedland variable area flow meters are very resistant to mechanical damage due to the separation of the measurement scale from the actual measuring element by the solid steel, brass or aluminum partition. The rotating scale provides an easy and clear reading. They do not require flow straighteners the instruments can be even mounted directly behind the 90° elbows. A reverse flow by-pass option is available and it has split metering cone. In this solution, the meter does not block flow even if the flow meter is impropely connected. Note that flow is measured always in one direction.

Features overview:

• Flow measurement: 0.5 – 380 lpm;
• Maximum pressure: 345 bar or 414 bar;
• Temperature range: from -29 to +116°C;
• Accuracy ±2% full scale;
• Repeatability ±1%;
• Port size: from G1/4″ to G1-1/2″.

Advantages:

• Easy to install;
• Operates in any position;
• Relatively insensitive to shock and vibration;
• Wide range of flow range;
• For caustic and corrosice liquids and for A.P.I. oils.