Abstract: The invention relates to a swivel adapter-coupler that is to be positioned between a conventional fixed drop elbow on the end of a hose of a tanker truck for an underground storage tank. The other end of the swivel adapter-coupler attaches to the pipe adapter (either the fill pipe or the vapor pipe) of the underground storage tank, in the conventional quick-connect type connection. The swivel adapter-coupler permits loops and kinks in the hose to be removed by rotating the swivel adapter-coupler in the proper direction. Likewise, the invention relates to a rotatable drop elbow to replace the conventional fixed drop elbow at the end of a hose on a tanker truck. The rotatable drop elbow eliminates loops and kinks in the hose by merely rotating the drop elbow in the proper direction.

Abstract: The invention relates to a swivel adapter-coupler that is to be positioned between a conventional fixed drop elbow on the end of a hose of a tanker truck for an underground storage tank. The other end of the swivel adapter-coupler attaches to the pipe adapter (either the fill pipe or the vapor pipe) of the underground storage tank, in the conventional quick-connect type connection. The swivel adapter-coupler permits loops and kinks in the hose to be removed by rotating the swivel adapter-coupler in the proper direction. Likewise, the invention relates to a rotatable drop elbow to replace the conventional fixed drop elbow at the end of a hose on a tanker truck. The rotatable drop elbow eliminates loops and kinks in the hose by merely rotating the drop elbow in the proper direction.

Abstract: A pressure control system for accurately controlling the pressure of the air in a discharge line during a pneumatic offload includes a blower, a supply of pressurized air and a pressure relief valve. The blower directs a stream of air into the discharge line to produce a positive air pressure. The pressure relief valve includes a valve body defining a hollow valve chamber, a valve positioned within the valve chamber and a valve seat opposite the valve. The valve chamber of the pressure relief valve is in fluid communication with the discharge line through a first inlet port and in fluid communication with the supply of pressurized air through a second inlet port that receives air from the supply of pressurized air. The valve chamber of the pressure relief valve is also in fluid communication with the ambient atmosphere through at least one outlet port.