Hardware Interchangeability with Metallic Cylinders
Case studies have shown that PolySlide® cylinder tubing can directly replace metallic tubing while keeping all the remaining cylinder components. This includes piston, seals, wear band, and other components. Pre-lubrication and cylinder assembly techniques can also remain the same. Polygon recommends each case be tested and approved by the customer.
|Material Type||Tensile Hoop (x103)||Elastic Modulus Hoop (x106) (psi)||Elastic Modulus Axial (x106) (psi)||Density (lbm/in3)||Material Specifications|
|Brass||20||15||15||0.32||C932 (SAE 660)|
|Steel||47||29||29||0.28||A513 T5 (1026)|
The General Property table shown above gives a basic comparison and overview of various cylinder materials in relation to PolySlide® products.
On this table the strength properties for PolySlide® are based on a standard cylinder design. However, for special applications, the strength properties can be varied significantly and in some cases the hoop strength can be doubled.
The following are case study summaries of performance comparisons between PolySlide® and other cylinders types under various conditions.
Case Study 1: High Load Pneumatic Test — Aluminum vs. PolySlide® Cylinders
This test compared the performance of PolySlide® cylinders with high quality aluminum cylinders. The test evaluated the cylinder temperature resulting from seal friction under high load conditions through a 5,000,000 cycle life test. Three sets of two cylinders were tested simultaneously under the same conditions for the purpose of reliable statistical data. In each set, the piston rods of each cylinder type were attached end-to-end so they would oppose each other in a similar manner as a SAE J214 setup. The 4" bore cylinders were stroked 7" at an average cycle rate of 15 cpm at shop pressure of 100+ psig. The following chart plots the average cylinder temperatures resulting from heat energy being generated from friction between the cup seals and the bore surface throughout the test. As can be observed from the chart the aluminum cylinders temperatures were higher than the PolySlide® cylinders throughout the latter 75% of the test.
Case Study 2: Bore Surface Wear Resistance Characteristics — Aluminum vs. PolySlide® Cylinders
In this example, Polygon was designing to replace an installed cylinder where minimal on-site maintenance can be expected. Polygon completed a test comparing wear characteristics of a 3" bore by 7" stroke aluminum and PolySlide® cylinders, cycling at 60 cpm continuously for 7,000,000 cycles. The test pressure was 80 psig.
The result showed that both cylinders suffered from O-ring seal destruction. However, the aluminum bore surface was deeply scored, while the PolySlide® surface did not have a scratch and was suitable to continue the test after O-ring replacement.
Case Study 3: Fatigue Characteristics — Disposable Stainless Steel vs. PolySlide® Cylinders
A 300 psig hydrostatic impulse test was performed on 1.06" bore non-tie rod stainless steel and PolySlide® cylinders until failure. The chart below shows the number of cycles completed by each cylinder before failure.
The failure mode for the stainless steel cylinder was a catastrophic failure in which the end cap blew off due to metal fatigue at the crimped joint connecting the end cap to the cylinder tube.
The failure mode of the PolySlide® cylinder was a weeping condition near the end cap. The end cap remained in place and the joint did not separate. This weeping condition is a common failure mode of the composite cylinder when the ultimate strength is being approached. It is a built in safety feature of PolySlide® in most applications by allowing for pressure to relieve before catastrophic failure.
Case Study 4: Large Cast Iron Cylinder Studies
A series of tests have been conducted comparing the performance of 10" bore PolySlide® with cast iron cylinders of the same size having a 150+ Ra bore finish. The cylinders were cycled 200,000 times at a cycle rate of 4 cpm with 80 psig test pressure. By-pass leakage was monitored at both high and low pressures. Various types of lubricants were evaluated in the various tests. Seal wear was considerably less in the PolySlide® cylinders than in the cast iron cylinders.
Any ratings are typical for design purposes. Your design parameters may affect final ratings. Consult with a Polygon sales engineer for guidance. Final testing and approval is the customer's responsibility for their application. This information is derived from our testing and published data. There is no assurance of these properties, or warranty provided that these products are suitable for any particular purpose or operational situation.
Polygon certifies that their product will be free from material defect. Polygon will not accept any liability for loss, damages, or costs from use or misuse of our products.
Specifications are subject to change, and may be affected by our continual process of improvement. Changes may be made without prior announcement.