Liquid level control valve assembly

A liquid level control assembly for use in connection with a liquid storage tank having an inlet through which liquid enters the tank under a supply pressure, said assembly comprising:

• a valve shiftable between a closed position preventing liquid from entering the tank through said inlet and an open position permitting said entry;
• and
• valve-operating means for opening said valve when the liquid level in said tank drops to a lower predetermined level and for then reclosing the valve when the liquid level rises to an upper predetermined level,
• said valve-operating means including a float and means for selective adjustment of said lower predetermined level,
• said valve-operating means including a normally upright element shiftable between a pair of upper and lower dispositions corresponding to closing and opening of the valve, respectively,
• said element having a pair of upper and lower ballast members attached thereto that are jointly operable to combine their gravitational effects when the liquid drops to said lower level and thereby effect said shifting of the element to said lower disposition thereof against any resistance from said float,
• said lower ballast member having means releasably attaching the same to said element for selective adjustment of the lower ballast member along the element.

A liquid level control assembly for use in conjunction with a liquid storage tank having an inlet through which liquid may enter the tank at a supply pressure, said assembly comprising:

• an inlet tube connectable at one end to said tank inlet in liquid flow communication therewith,
• said tube having an annular valve seat at the opposite end thereof;
• a valve diaphragm across said opposite end and flexible toward and away from said seat;
• a sleeve receiving said tube in concentric relationship therewith and defining an annular passage therebetween,
• said sleeve having an annular terminus substantially flush with said opposite end of the tube and underlying a marginal periphery of said diaphragm;
• interengageable interlock means between said tube and the sleeve operable to retain the same in said relationship with said opposite end and said terminus substantially flush upon manual relative rotation of the tube and the sleeve to effect said interengagement;
• a cap threaded onto said sleeve and having a cavity registered with said diaphragm and receiving the latter when flexed away from said seat,
• said cap further having an annular abutment overlying said marginal periphery of the diaphragm and cooperating with said annular terminus of the sleeve to clamp the diaphragm in place,
• said cavity in the cap defining a chamber on the side of said diaphragm opposite said seat and said diaphragm having a pilot orifice therein communicating said chamber with the interior of said tube,
• the exposed surface area on the chamber side of the diaphragm being greater than that exposed to the interior of said tube when the diaphragm is against said seat;
• a bore through said cap communicating said chamber with the exterior of the cap;
• a pilot valve operable within said bore between a position sealing the same and a position opening the same,
• said valve having a stem that projects through said bore and beyond adjacent external surfaces of the cap when the pilot valve is in said sealing position thereof;
• a tubular housing concentrically receiving said sleeve and extending a substantial length of said tube,
• said housing being reciprocable longitudinally of the tube and sleeve between upper and lower limits corresponding to said closing and opening of the diaphragm, respectively,
• said housing having an open upper end through which the sleeve, cap and tube may be inserted during assembly;
• a closure for said open end of the housing;
• manually interlockable structure on said closure and the housing for retaining the closure in place after insertion of said sleeve, cap and tube,
• said closure having an operating surface engaging said stem of the pilot valve;
• and
• float-ballast means manually detachably secured to the exterior of said housing for buoying said housing up to said upper limit when the liquid in said tank reaches an upper predetermined level to thereby seal said pilot valve and cause flexure of the diaphragm against said seat to close said opposite end of the tube, but for gravitationally pulling said housing down to said lower limit and thereby open said pilot valve to permit flexure of the diaphragm away from said seat to thereby open said opposite end of the tube when the liquid drops to a lower predetermined level in the tank.