4V-500 ½â-2â Modification Overview Production of the 4V-500 PVB began in 1998. The 4V utilizes a float assembly that contains a relief valve that protects the unit against…

40-500 ½â- 2â Modification Overview Production of the 40-500 PVB began in 1991 and was discontinued in 2003. Canopy Removal The canopy is secured by two screws. Bonnet…

765 ½â- 2â Modification Overview Production of the 765 began in 1975 and is current. Canopy Removal The canopy is secured to the bonnet with a lock nut. Bonnet Removal…

PVB-4A ½â- 2â Modification Overview Production of the PVB4A series began in 2008 and is current. Canopy Removal The canopy is secured by two screws. Bonnet Removal The…

800 (M2,M3,M4) ½â-2â Modification Overview The original model 800 was produced from 1982-1993. The 800M2 was produced from 1991-1994. The 800M3 (1/2â,3/4â sizes only)…

420, 420XL ¾â-1â Modification Overview Production for the 420 began in 1998. The first version of the 420 had male threads on the body and female threads on the bonnet.…

765 ½â- 2â Modification Overview Production of the 765 began in 1975 and is current. Canopy Removal The canopy is secured to the bonnet with a lock nut. Bonnet Removal…

800 (M2,M3,M4) ½â-2â Modification Overview The original model 800 was produced from 1982-1993. The 800M2 was produced from 1991-1994. The 800M3 (1/2â,3/4â sizes only)…