as shown in fig7 which allows it to grow in diameter as the sliding sleeve moves from the closed to open position locking ring holder 25 has sufficient diameter clearance so that the locking ring can ratchet on the mandrel ratcheting teeth 63 yet never loose threaded contact with the lock ring holder locking ring holder 25 is threaded at 26 for engagement with threads 24 on the mandrel locking ring holder 25 also has a plurality of bores 46 and 62 for set screws not shown in use valve 10 may be connected to the casing string by end connectors 11 12 one or more valves 10 may be incorporated into the easing string after the casing string is deployed within the well cement is pumped down through the casing and out the bottom into the annulus between the well bore and the casing as typical in the art after the cement flow is terminated a plug or other device is pumped down to wipe the casing and valve clean of residual cement when the plug or other device has latched or sealed in the bottom hole assembly pressure is increased to rupture the rupture disk at a predetermined pressure the fluid pressure will act on sliding sleeve member 20 to cause the shear pins to break and then to move it downward or to the right as shown in fig7 this movement will allow fracing fluid to exit via opening 23 in the mandrel and openings 19 in the outer housing the fracing fluid under pressure will remove protective cover 40 and crack the cement casing and also fracture the foundation adjacent to the valve 10 due.