Common Questions: Which valve series does this bonnet fit

Whether you are performing a 1:1 replacement for a V4055A1031/U or upgrading an existing safety train

It is designed exclusively for hot and chilled water applications in closed-loop hydronic systems

Direct Replacement: Serves as the factory-authorized update for the legacy Lochinvar VAL3213 part number

System Reliability: Eliminates "Pressure Switch Stuck Open" or "Failed to Close" fault codes common in high altitude HVAC installations

AERCO GP-18900 Seal 320734-701 Common Questions: Which valve seriesThe AERCO GP 18900 Seal is a critical genuine OEM replacement part specifically engineered for high performance AERCO boiler parts and commercial water heating systems. This precise manifold to lower head seal is designed to create a robust, leak proof interface between the manifold and the lower head assembly, ensuring pressure integrity and thermal efficiency. As an authentic HVAC replacement seal, the GP 18900 prevents bypass leakage and maintains