Automatic Casing, Hanger (PCHA) is basically designed for heavy load service and is used for PARVEEN's Casing Head Housing 'PCHH' and Casing Head Spool 'PCHS' described earlier. When the Casing load is applied to the hanger, the top ring connected by the Pack-off and shoulder screw compresses the packing to seal the annulus pressure of the casing. This casing hanger is normally used for pressure ratings upto 3000 PSI. For ratings over 3000 PSI, type 'PSPO' Pack-off is used to prevent collapse of the pipe.
Unitised Casing Hanger (PCHU) can be used both for PARVEEN's Casing Head Housing (PCHH) and Casing Head Spool (PCHS) as described earlier. This Hanger is designed for medium or heavy load service. This hanger is normally latched around the pipe and lowered in casing head body. After the casing is landed, shoulder screws should be evenly tightened to affect a positive annular seal. The hanger may be used upto 3000 PSI WP. For ratings over 3000 PSI, 'PSPO' Pack-off is used to prevent collapse of the pipe.