The Lee Spring catalog has always offered springs with relatively low spring rates or workable (maximum) loads. But often, established sizes had diameters (outside or inside) too small to accommodate the intended application assembly requirements. Lee Spring’s "Lite Pressure™(LP) Series offers lower spring rates or workable load ratings for a given length and diameter than what is offered in the Lee Spring Instrument Compression (CI/CIM) or Standard (LC/LCM) Compression Spring Series.
Why "Pressure"? Pressure is described as a force which is exerted over a surface area. In regards to compression springs, the pressure exerted as the result of a specific deflection can be more technically described as force over a flat surface with a circular perimeter (the Nominal Hole in which the spring is being used). The term "Lite Pressure™" refers to the design performance of these springs, generally used where relatively low forces are required for a given diameter.
How Pressure Rating for LP Series Would Be Used: The pressure rating assigned to each item of the Lite Pressure™ series is a selection parameter to assist in meeting qualitative requirements or quantitative requirements. Each series is offered in a range from 1 to 5 psi pressure ratings, in 1 psi increments.
LP series springs are ideal for many fluid power applications such as relief valves, check valves or pistons. Other miscellaneous applications could include motor brushes, contacts, displays, syringes, toys, dispensers and many more, especially assemblies requiring low forces over a long deflection.
LP series springs are offered ONLY in passivated and ultrasonically cleaned Type 316 Stainless Steel in order to meet requirements in various diverse applications that call for improved corrosion resistance, enhanced cleanliness, and moderately elevated temperatures. Click here to Request a Custom quote using other materials and or sizes.
Relationship To Fluid Pressure: The pressure ratings used for Lite Pressure™ Series springs have no direct relationship with "pressure" as traditionally used in the fluid power industry, although indirectly the pressure ratings are conceptually equivalent. Fluid pressure would be the result of a spring force acting over the specific area exposed to the fluid and would depend on other application components such as the valve face or the piston head
Example: Calculation of Pressure, LP 014E 05 S316
Nominal Hole: 0.375 inch
Free Length: 1.000 inch
Solid Height: 0.143 inch
Spring Rate: 0.161 lbs/inch
- The maximum recommended pressure for this spring will occur when the spring is at 80% of maximum available deflection; generally it is not recommended to use a compression spring all the way down to solid height.
- The maximum available deflection is the difference between the Free Length (1.000) and the Solid Height (0.143) or 1.000 - 0.143 = 0.857 inch.
- 80% of that would be 0.857 x 80% = 0.686 inch.
- The calculated load at this deflection would be the deflection (0.686) times the Spring Rate (0.161) or 0.686 inch x 0.161 lbs/inch = 0.110 lbs.
- The surface area over the Nominal Hole diameter (0.375) would be pi (?) times the diameter squared divided by four or pi (?) x (0.375)2 / 4 = 0.110 in2.
- The resultant pressure would then be determined by dividing the calculated load by the surface area or 0.110 lbs / 0.110 in2 = 1 lb/in2 (psi).