Abstract: An explosion relief valve for a crankcase of an engine includes a carrier plate, a cap, and an annular flame arrestor. The carrier plate includes a valve plate that has a sinuous shape for redirecting flame back into the engine. The flame arrestor includes a plurality of layers of smooth metal sheets, with each layer having a pattern of apertures that is different in size and spacing than the pattern of apertures of its adjacent layer. The apertures of each layer are partially, and only partially, aligned with the perforations of its adjacent layers. The layers are laid flush against each other to minimize or eliminate air space between the layers, leaving only the air channels existing between the apertures of the metal sheet layers as passageways for exhaust gases to be released from the valve.

Abstract: The sealable and lockable valve box lid assembly disclosed herein provides a water-tight seal between the valve box and ground surface, is capable of supporting heavy downward loads created by vehicle traffic, and has a low vertical profile that is suitable for shallow valve box installations.

Abstract: An explosion relief valve for a crankcase of an engine includes a carrier plate, a cap, and an annular flame arrestor. The carrier plate includes a valve plate that has a sinuous shape for redirecting flame back into the engine. The flame arrestor includes a plurality of layers of smooth metal sheets, with each layer having a pattern of apertures that is different in size and spacing than the pattern of apertures of its adjacent layer. The apertures of each layer are partially, and only partially, aligned with the perforations of its adjacent layers. The layers are laid flush against each other to minimize or eliminate air space between the layers, leaving only the air channels existing between the apertures of the metal sheet layers as passageways for exhaust gases to be released from the valve.

Abstract: An explosion relief valve for a crankcase of an engine includes a carrier plate, a cap, and an annular flame arrestor. The carrier plate includes a valve plate that has a sinuous shape for redirecting flame back into the engine. The flame arrestor includes a plurality of layers of smooth metal sheets, with each layer having a pattern of apertures that is different in size and spacing than the pattern of apertures of its adjacent layer. The apertures of each layer are partially, and only partially, aligned with the perforations of its adjacent layers. The layers are laid flush against each other to minimize or eliminate air space between the layers, leaving only the air channels existing between the apertures of the metal sheet layers as passageways for exhaust gases to be released from the valve.

Abstract: An explosion relief valve for a crankcase of an engine includes a carrier plate, a cap, and an annular flame arrestor. The carrier plate includes a valve plate that has a sinuous shape for redirecting flame back into the engine The flame arrestor includes a plurality of layers of smooth metal sheets, with each layer having a pattern of apertures that is different in size and spacing than the pattern of apertures of its adjacent layer. The apertures of each layer are partially, and only partially, aligned with the perforations of its adjacent layers. The layers are laid flush against each other to minimize or eliminate air space between the layers, leaving only the air channels existing between the apertures of the metal sheet layers as passageways for exhaust gases to be released from the valve.

Abstract: An explosion relief valve for a crankcase of an engine includes a carrier plate, a cap, and an annular flame arrestor. The carrier plate includes a valve plate that has a sinuous shape for redirecting flame back into the engine. The flame arrestor includes a plurality of layers of smooth metal sheets, with each layer having a pattern of apertures that is different in size and spacing than the pattern of apertures of its adjacent layer. The apertures of each layer are partially, and only partially, aligned with the perforations of its adjacent layers. The layers are laid flush against each other to minimize or eliminate air space between the layers, leaving only the air channels existing between the apertures of the metal sheet layers as passageways for exhaust gases to be released from the valve.