Valve and Flow Control Specialists offer a range of valve actuation in electric, hydraulic and pneumatic options. These options can suit small valves such as ball valves through to large bore (1400NB) valves such as butterfly or knife-gate valves. Thus actuators will suit quarter turn operation or linear operation.
TYPES OF VALVE ACTUATION
The most basic actuation of operator assisted valve operation is that of chainwheel or gearbox chainwheel units. To save the complexities of “working at height” usually anything above 2 meters a chainwheel can be retrofitted to an existing manual gate or globe valve (known as a multiturn valve) so it can be operated from floor level. For ball valves or butterfly valves (quarter turn valves) a gearbox chainwheel unit mount is used.
Electrics can be AC/DC or 3 phase 415v and can be fail in last operation or failsafe. Pneumatics can be linear operated via a diaphragm on top or quarter turn in both scotch yoke or rack and pinion designs. The rack and pinion designs are the most popular in the small to medium sized valves depending on the style up to around 250nb size. Hydraulic actuators operating on fluid can also be an excellent alternative for medium to large valves or if there is no air supply to operate pneumatics.
New valve actuation technology such as Hydrogen powered actuation is gaining momentum in some markets however it is currently a niche application. We offer the actuators as individual items or pre-mounted and tested to the required valves. Remember if mounting actuators yourself to valves or dampers you will need drive inserts to suit the valve stems.
ACCESSORIES
Due to the amount of project involvement and site specific requirements or preferences across the Asia Pacific Areas we are well versed in supplying and mounting an array of actuation. The most popular being ROTORK, BERNARD, AUMA, LIMITORQUE, BETTIS, VALPES, BIFFI, ARITA and SCHISCHEK.
We also distribute accessories such as the drive adaptors. mounting brackets, stem extensions, solenoids, filter regulators, limit switches/ indicators, positioners, volume boosters and a range of INTERLOCK safety devices for lever, gear op and Actuated systems. Apart from the standard versions of solenoids and limit switch boxes we also offer the variations in Ex ia intrinsically safe and Explosion proof Ex d.
Pneumatic (air operated) Actuators
Quarter turn or 90 degree operation Actuators
The DFS Actuator is the basic popular 2 piston version of the rack and pinion style units found on most quarter turn valving like ball and butterfly valves. It is available in normal Double Acting and Spring Return.
Dux upright cylinder actuators are an option to the Scotch Yoke big bore actuators but much more compact. Unlike Scotch Yokes they are available in standard 90 degree and also 120 or 180 Degree variable operation. This makes them suitable for 3 way diverting valve applications.
The 4 piston units are a very compact actuator, are much more effective and longer wearing due to their smaller strokes and size. These units are the preferred style in the transport industry.
The Scotch yoke versions of the pneumatic series are more expensive than the DFS rack and pinion series however they are better suited to butterfly valve operation. For large bore butterfly valves, ball or plug valves scotch yoke style actuators have to be used as the physical attributes and torques factors far exceed the rack and pinion style actuators.
The Gemini Actuators are extremely well made actuator out of the USA giving excellent reliability and longlivity on ball valves. For the past 40 years they have operated in an acid fume environment at one particular site where others have failed. A great compact actuator ideally matched to a Gemini ball valve.
Full turn or 180 Degree Actuators
The majority of pneumatic actuators are quarter turn however full-turn or 180 Degree is sometimes required on diverting valves. The 180 degree rack and pinion pneumatic actuators therefore switch flows in a valves operation. They can be double acting or spring return. The spring return units can be set up to fail on air loss to either position once setup. There are 5 models / sizes ranging up to 221nm torque (if 5.5bar air)
For 120 or 180 degree variable operation also refer the DUX actuators above.
Diaphragm Actuators for both Linear and quarter turn Control Valves
Linear Diaphragm Actuators operate with the conventional globe style valves. They are relatively inexpensive and used for low to medium thrust ranges. Stem adaptors are available to suit most valve stems, contact us for details.
Diaphragm Actuators for quarter turn valves operate in the same principle except have a cam to convert the thrust force to quarter turn rotation. We also carry spare diaphragms for the Valvitalia DRA 13 and DRA 18 series actuators in stock.
Hydraulic (fluid operated) Actuators
Hydraulic actuators operate with higher operator pressures giving high torques. This quarter turn unit is ideal on butterfly valves or other rotational devices.
Duxdrive Actuators are a compact upright actuator that give 90 / 120/ 180 degree operation making them a very versatile actuator for straight through and diverting valves.
Electric Actuators
Electric Actuators are available for both quarter turn types (ball or butterfly valves) and multiturn for globe type control valves and gate valves. For the linear type valves a matching type of electric actuator can also be offered typically though only in the globe type which have short travels.
For those units going into hazardous areas we offer ATEX or IECEx certified versions of the quarter turn, multiturn and linear types.