Deaerator system having positive pressure indicating means

An improved deaerator system for purging air from water comprising:

• container means for containing the water, input means for establishing a positive gas pressure within the container, a first conduit leading from the container at a point above the normal level of water in the container and having a distal end extending in a substantially downward direction, a substantially downwardly extending check valve connected in fluid communication with the first conduit distal end, the check valve including an upstream sleeve, a downstream sleeve, an annular valve seat member disposed between the upstream sleeve and the downstream sleeve, valve head guide means extending from the valve seat, a valve head carried by the guide means, and biasing means for urging the valve head into seating, valve-closed engagement with the valve seat under normal conditions but permitting the valve head to open in a downstream direction away from the valve seat in response to excessive pressure experienced in the upstream sleeve, the system further including positive fluid pressure indicator means having an indicator housing, a second conduit providing fluid communication from a point located on and in the check valve upstream sleeve but spaced apart from the valve seat, to the valve housing bottom, the housing having a substantially vertically disposed through-bore communicating at its bottom with the second conduit, a seat being formed within said through-bore, the indicator means further including an indicating element disposed within said bore, said indicating means being arranged to engage the through-bore seat in the absence of positive pressure within the container means and through-bore, and to disengage said seat and rise in said through-bore in response to positive pressure within the container means and the check valve upstream sleeve, the indicating element being viewable through the housing when disengaged from the seat to provide a readily discernable indication of positive pressure within the container means, and being weighted to rise from the through-bore seat in response to a pressure which is less than that required to unseat the check valve head from its valve-closed position on the check valve seat.