The Groth 1400 Series valves provide safe, dependable, and accurate low pressure and/or vacuum protection. Seals in accordance with API 2000 requirements for Pilot Operated Relief Valves. This design prevents fugitive emissions and conserves stored product. Rated flow at less than 10% overpressure provides the ability to operate closer to the tank MAWP, increasing the operating range of the process. This reduces the need for a large overpressure and saves product, which translates into profit. Flexibility in snap or modulating action allows product customization to specific application requirements. Blowdown may be adjusted to requirements between 0 and 10% of set pressure. The Models 1400 and 1420 incorporate a vacuum breaker.