Actuated Flow Control
An actuator is something that converts energy into motion. It also can be used to apply a force. An actuator typically is a mechanical device that takes energy — usually energy that is created by air, electricity or liquid — and converts it into some kind of motion. That motion can be in virtually any form, such as blocking, clamping or ejecting. Actuators typically are used in manufacturing or industrial applications and might be used in devices such as motors, pumps, switches and valves.
GEORGE FISCHER PIPING SYSTEMS has the optimal actuator configuration for your individual needs. George Fischer offers electric and pneumatic actuation for diaphragm, ball and butterfly valves. Coupled with the actuator are several control options to compliment sophisticated plant management.
Chemical process industry; life science; microelectronics; measurement & control; water treatment; ship building.
George Fischer has custom designed actuators for the complete range of valves. These include:
- Pneumatic versions for Diaphragm, Ball and Butterfly Valves, with the options of fail-safe-close, fail-safe-open or double acting variants;
- Ball and Butterfly Valves are also offered with a manual override option;
- In addition to the pneumatic option, electric actuators (motorised) are available for ball and butterfly valves;
- When coupled with the complete range of Instrumentation, actuated valves are able to be controlled through computerised systems using conventional 4-20mA signals as well as ASI* communication. Also available is a range of controllers for I to P** systems.
* Actuator Sensor Interface
** "Current to Air Pressure" conversions
Plastic pipe dimensions are, by convention, specified by the outside diameter, usually denoted by e. This may be supplemented by stating the nominal inside diameter or DN. Sometimes the pipe wall thickness is specified by the SDR or Standard Dimension Ratio.
SDR = d divided by e.
Where d = the outside diameter (mm)
Where e = the pipe wall thickness (mm)
The pipe size can be calculated as follows:
di = 18.8 √Q1 ÷ v
di = Inside pipe diameter (mm)
Q1 = Flowrate in m3/h
v = Flow velocity, usually 0.5 to 1.0 m/s for suction lines
1.0 to 3.0 m/s for discharge lines.
Material α = mm/mK ABS 0.10 PE 0.15-0.20 PP 0.16-0.18 PVC-U 0.07-0.08 PVC-C 0.06-0.07 PVDF 0.12-0.18
A rough calculation of pressure loss in straight length plastic pipe can be done using,
Δ Pr = λ × (L ÷ di) × (ρ ÷ 2.102) × v2
Δ Pr = Pressure loss (bar)
λ = Pipe friction factor
L = Length of straight pipe (m)
di = Inside pipe diameter
ρ = Liquid density (kg/m3)
v = Flow velocity (m/s)
For smooth bore plastic pipe: λ = 0.02