The Waterco 2 inch top and side mount valve spring is designed for compatible multiport valve applications where the spring element inside the valve needs replacement. A spring in this role is useful because it helps maintain proper movement, return force, or engagement inside the valve mechanism depending on the supported design.This replacement is especially useful when the original spring has weakened, corroded, deformed, or failed to the point that valve action no longer feels correct. Small internal components like springs can have a major effect on how cleanly a multiport valve operates.The 621181 is a practical repair part when a compatible 2 inch Waterco valve needs internal spring performance restored for smoother, more reliable operation. Waterco 2 inch top and side mount valve spring Designed for compatible internal valve mechanism service Helps restore correct movement and engagement inside the valve Useful when the original spring is weak or damaged Supports a more complete internal valve repair