1. Technical Requirements for Compression Springs

1. Both ends are tightly clamped and ground smooth for 3/4 of a turn, with one support ring at each end.
2. The spring’s length-to-diameter ratio H÷D ≤ 3.7 (H: free height, D: mean diameter)
3. Spring helix angle θ = 5–9°
4. Maximum spring deflection/compression deformation ≤ 82%
5. Spring index: D ÷ d = 4–15 (D: mean diameter of the spring, d: wire diameter)
6. Spring sleeve or mandrel guide height h = 1.5d (short guide)
7. Spring sleeve or mandrel guide clearance a

8. Spring Accuracy Grade Table

2> Spring steel wire material

3> Butterfly spring guidance and pre-compression deformation amount

1. The guide for disc springs shall be provided by a guide rod or a guide sleeve. The guide clearance ‘a’ is shown in the table below, and internal guidance should be preferred for disc springs.

2. The pre-compression deformation amount f of the butterfly spring used for packing seal compression

f=0.6～0.8h ₀ (h ₀ =Flat deformation of the disc spring)

4> Minimum wall thickness of stainless steel cast housings (uniform wall thickness for pressure ratings of 25 bar to 100 bar)