DK-Lok RVS Series Relief Valve Springs, Colour Coded

In a DK-Lok relief valve the spring holds the disc on its seat until the line pressure overcomes it. Which spring is fitted therefore sets the band the valve can be adjusted within, and the adjusting screw only moves the setting inside that band. Choosing the spring is part of specifying the valve, and the V66 is supplied without one for that reason.

Each spring is wound from stainless steel 302 and carries a colour code so the range fitted can be identified without dismantling the valve. Nine ranges are listed. Eight of them are for the V66 series and step from 50 psig up to 6,000 psig; the ninth, red-coded RVS-L, covers 10 to 225 psig and is the spring used in the V63.

Springs are ordered as spares when a valve is re-ranged for a different duty, when an existing spring has taken a set or corroded, and as stock held against maintenance of instrument and gauge protection, hydraulic and pneumatic systems, test benches and process and utility lines.

When ordering, give the valve series the spring is for and the cracking pressure required, and quote the spring designator from the specification table. The bands overlap at their limits, so where a setting falls on a boundary — 350 psig, say — state the pressure and the direction it will be adjusted in.