PAL Pneumatic Isolators
PAL-type pneumatic isolators provide superior low frequency vibration isolation. These isolators are ideally suited for conditions where height control and low frequency vibration control must co-exist. Fabreeka PAL isolators meet the critical needs of metrology instruments, electron microscopes, inspection stations and precision manufacturing equipment.
Associated Applications:
Metrology
MRI/NMR
Precision Equipment
Test Equipment
Key Features/Benefits:
The standard Fabreeka PAL isolators have a natural frequency as low as 1.7 Hz, however, lower natural frequencies (0.5 Hz) can be obtained from custom designed isolators.
PAL isolators react quickly to changes in the supported load and to center of gravity shifts by automatically releveling to a preset position.
Can support payloads from 100 to 120,000 lbs per isolator.
Settling time is minimal with optimum damping and corresponding valve flow.
What is the leveling accuracy of the PAL isolators?
The leveling accuracy of the PAL isolators depends on the type of valves used. The standard FLV-4 valve has an accuracy of +/-0.005”, while the optional FLV-7 valve has an accuracy of +/-0.001”.
What are the vertical and horizontal damping values for PAL isolators?
The vertical damping value of a PAL isolator is adjustable by 6-20% on all standard sizes, while the horizontal damping is 3-6% depending on the isolator type.
Will you explain transmissibility/percent isolation?
The transmissibility of an isolator is a relative measure given as a ratio of output amplitude to input amplitude. The lower this ratio, the greater isolation an isolator provides.
Which leveling valve is recommended for my application?
The standard PAL isolators use the FLV-4 valve, which is suitable for most applications. If the isolated mass has a distance between isolators less than three times the vertical center of gravity, is supported by only three isolators or a large moving mass, a FLV-7 valve may be necessary. Large systems may require higher flow valves. Please contact Fabreeka's Engineering department at 1-800-322-7352 or info@fabreeka.com to discuss your specific application.
What size PAL isolators should I use for my application?
PAL isolators are sized based on the total supported mass and the number of isolators used. All isolators have a maximum load capacity at 100 psi, which should not be exceeded. All isolators should have a working pressure within 15 psi of each other for stability.
What type of tubing should be used to connect to my air supply?
All tubing and fittings used for our pneumatic systems should be rated for a minimum of 120 psi working pressure. 1/4" OD tubing is a minimum recommendation. Tubing and fittings are supplied with our systems.
What are the major design parameters/calculations when choosing pneumatic isolators to isolate my equipment?
In order to select a pneumatic isolation system, the following information is necessary:
- Isolator frequency and damping required for isolating equipment (may require a vibration survey)
- Total weight of isolated mass
- Number of isolators, based on geometry
- Center of gravity of isolated mass
- Any moving mass on equipment
What is the air consumption of a PAL system?
The air consumption is determined by the valves used in the system. The maximum consumption is 16 scfm at 100 psi during the initial filling, but if less is available, it will simply take longer to fill the isolators. During normal operation, the system will consume zero to 4 scfm, depending on how much the isolated mass moves.
