Pressure-balanced stem designs incorporate small-diameter relief holes or equalizing ports that reduce the net force required to actuate the valve under high differential pressure. This lowers torque requirements and protects stem seals from excessive side loading. API 6A allows pressure balancing only if the design is proven not to compromise stem sealing integrity during rapid press... https://globalsealstech.com/product-category/oil-gas-seals/api-6a-gate-valve-seals/