![Axial Flow Relief Valve Axial Flow Relief Valve](http://www.samsoncontrols.com/sites/default/files/AxialFlow_1.png)
Flow through a screw pump is axial and in the direction of the power rotor. The inlet hydraulic fluid that surrounds the rotors is trapped as the rotors rotate. This fluid is pushed uniformly with the rotation of the rotors along the axis and is forced out the other end. A relief valve prevents excessive pressure buildup by routing high.
Control Seal has a UNIQUE DESIGN OF ITS PRODUCTS, SHORT LEAD TIME, COMPETITIVE PRICING AND EXCELLENT AFTER-SALES SUPPORT.The Control Seal Axial Flow Valve has the following distinguishing features:QUARTER TURN STEM DESIGNEccentric disk connected to the rotating stem to move the piston rod practically frictionless, compared to a gear-rack which loses more than 50% of its thrust.Compact actuator due to reduced friction of inside mechanism and balanced piston. Moreover the rotating actuator has a lower stem friction.High-end stem packing design avoiding fugitive emissions along the stem.Available in different trim characteristics - cage design (linear, equal percentage, modified stage).ADVANCED SEALING MECHANISMBubble tight shut-off to ANSI class VI, independent of actuation method. Fire safe shut-off to ANSI class V.Option for dual sealing consisting of two independent mechanisms: a metal-to-metal seal in combination with special design soft seal.No erosion impact on the seals and noise reduction. Soft seals not in contact with high flow due to special design concentric cage.FIRE SAFEFire safe according to API 6FA. Fully Open positionAxial Flow Valve is fully open, allowing full flow through the streamlined flow path egg shape body.2. Controlling the flowRotational movement of the vertical stem (dark yellow circle) is transfered to the horizontal movement of the stem and piston (yellow) by patented mechanism. The piston travels through the cage (red) and closes the holes in the cage based on its position.
Holes are distributed in the cage based on desired control characteristics.3. Fully Closed positionOn 90 degrees turn of the vertical stem, the valve reaches its fully closed position.
If the pressure downstream or back pressure of the relief valve is lower than the critical flow pressure, then the flow is said to be of critical type. In this case, the actual pressure downstream to the relief valve cannot fall below the critical flow pressure even if much lower pressure exists further downstream to the valve.
Mass flow relieved cannot increase any further, for the given set of flow conditions upstream to the valve.In the present case, back pressure (1.5 bara).