Pentair Pneumatic Actuators F257
Vertical quarter turn Pentair Pneumatic Actuators F257 are used to drive butterfly, ball and shutter type valves. The pneumatic actuators are commonly used in all segments of hygienic applications.
Product Description
Benefits
- Fast and reliable quarter turn operation makes it suitable for use with butterfly, ball and plug valves
- Only one external air supply line is required with our internally air ported actuator, when used with the Pentair control top on 100 & 140 sizes.
- Constructed from corrosion resistant materials
- Designed with an optimized piston helix to provide maximum torque output
- Double acting or spring return models available
- Fully contained spring module, to ensure complete safety to maintenance personnel
- Maintenance friendly
- Site repairable
- Modular bridge clamp mounting for easy actuator change-out on 100 & 140 sizes
Functional description
Pentair Pneumatic Actuators use an unique helix to convert liner motion of the pistion into 1/4 turn rotary action. On some sizes the helix is characterized to optimize the generated output torque.
The Pentair Pneumatic Actuators can be supplied in two configurations, Spring return (SR), or Double acting (DA) and the SR models can be configured in the valve build up to provide a mechanical fail to close or fail to open condition.
Fields of application
The pneumatic actuators are made from corrosive resistant materials and clean lines important for applications in the food, dairy, brewing, pharmaceutical, beverage and chemical industries. The Pentair Pneumatic Actuator Vertical SS in combination with the Easymind Electronic Control Top creates a simple and cost effective automation package for all 1/4 turn valve options.
Technical data
Air supply:
Double acting (DA)
300kPa (3bar) to 800kPa (8bar) max
Spring return (SR)
550kPa (5.5bar) to 800kPa (8bar) max
Maximum output torque:
Refer to torque curves or actuator selection
guide.
Product Information
Bracket Dimensions
| Valve sizes | Dimension | |||
| F250 | F251 | C | ||
| Inch OD | Metric | F257 065 | F257 100 | F257 140 |
| 1.0″-1.5″ | 25-40 | 41 | 24 | * |
| 2.0″-2.5″ | 50 | 41 | 25 | * |
| 3.0″ | 65-80 | * | 32 | 32 |
| 4.0″-5.0″ | 100-125 | * | 32 | 35 |
| 6.0″ | 150 | * | 35 | 35 |
Note: Dimension C will allow you to calculate the overall height of a F250/F251 valve and actuator arrangement. *Not available
Parts List
| No. | Description | Material | Standard |
| 1 | Base plate | 316 stainless steel | ASTM A743 CF8M |
| 2 | Output shaft | 303 stainless steel | AISI 303 stainless steel |
| 3 | Cylinder | 304 stainless steel | ASTM A269-A270 |
| 4 | Top plate | Polymer/304 stainless steel | – |
| 5 | Blank head | Polymer | – |
| 6 | Control head | See note* | – |
| 7 | Drive boss | 304 stainless steel | AISI 304 stainless steel |
| 8 | Bracket | 304 stainless steel | AISI 304 stainless steel |
| 9 | Set screw | 304 stainless steel | AISI 304 stainless steel |
Note: *Refer to separate F783 Easymind literature sheet for full details.
Actuator Weights
| Model | Mass (kg) | |
| F257 065 | DA SR |
2.65 2.65 |
| F257 100 | DA SR |
4
6 |
| F257 140 | DA SR |
11
14 |
Note: Weights are nominal and include mounting kits and F783 Control Head. DA Double Acting. SR Spring Return.
Pneumatic actuator selection chart for F250 and F251 Butterfly Valves
This actuator selection chart is a guide to the anticipated maximum torque required to operate the valve under the stated conditions. It includes seating, unseating (break-away), running torques and allows for stem bearing frictional forces. No additional safety factors are considered necessary unless the operating conditions are beyond the stated duties.
Service Definitions
Normal service: When used with clean lubricating fluids at ambient temperature and at a maximum of 1000kPa (10bar).
Severe service: All other applications.
Notes: For spring to open actuator selection, consult factory.
F257 Double Acting Pneumatic Actuator – Normal Service
F257 Spring to Close Pneumatic Actuator – Normal Service
F257 Double Acting Pneumatic Actuator – Severe Service
F257 Spring to Close Pneumatic Actuator – Severe Service
Typical Torque Curves – F257 Actuators
Notes: To determine the torque output of Air Assisted Spring to Close actuators, add the SR Close (Unassisted) torque value to the Double Acting torque value. The following points must be considered when selecting a suitable actuator:
- What size valve is to be actuated?
- Is the actuator to have an unassisted spring return?
- What service conditions is the valve to operate in (i.e elevated temperatures, dry, wet etc.)?
If you should have any doubts please contact your sales representative. For other air supply pressures contact your sales representative. Refer to F257 Actuator Selection Chart on previous page for sizing details.
DA Double Acting
SR Spring Return
Refer to F783 Control Head literature sheet for details on how to order the Control Head. Actuators will be supplied with bare tops unless ordered with Control Heads or Blank Heads.
Warning: PENTAIR actuators are factory lubricated and do not need lubricated air. Also the use of synthetic oils and some mineral oils are known to be damaging to polymer components. It is therefore recommended that clean dry air be used.
Selection Guide
