Constant spring support supplies a constant force to the pipe no matter how much the pipe moves against it, whereas a variable spring support supplies a variable force at some proportion of the amount the pipe moves against it.
"People will work for you with blood and sweat and tears if they work for what they believe in......" - Simon Sinek
Variable springs are also typically much smaller and much cheaper than constant load springs. Constant load springs are generally reserved where you have large vertical displacements such that the load change you would get with a variable spring become excessive.
Edward L. Klein
Pipe Stress Engineer
Houston, Texas
"All the world is a Spring"
All opinions expressed here are my own and not my company's.
