Abstract: A line blind valve is disclosed which includes a housing having opposed similar housing halves with resilient sleeve units which compressibly engage each other in the valve open condition and engage opposite sides of the gate or blind in the valve closed condition. The line blind valve provides visibility of all gate edges so as to give a positive indication that the gate or blind has passed completely through the seals. Lockout is also provided when the gate or blind is closed. Each sleeve unit has a plurality of compression holes extending axially and arranged at intervals relative to the circumference of the sleeve. An encircling stiffening ring of harder material is encapsulated in each sleeve so as to be positioned at the inner end of the compression holes. The line blind valve construction of the present invention results in no leakage to the outside when the valve is fully open and no leakage to the outside or past the gate internally when the valve is fully closed.

Abstract: A packingless gate valve is disclosed which includes a housing having opposed similar housing halves with resilient sleeve units which compressibly engage each other in the valve open condition and engage opposite sides of the gate in the valve closed condition. Each sleeve unit has a plurality of compression holes extending axially and arranged at intervals relative to the circumference of the sleeve. An encircling stiffening ring of harder material is encapsulated in each sleeve so as to be positioned at the inner end of the compression holes. The compression holes may be left empty or, alternatively, may be sealed with plastic plugs, filled with closed cell foam or mechanical springs. The compression holes provide space for the displaced volume of sleeve elastomeric material to flow into during opening and closing of the gate.

Abstract: A packingless gate valve is disclosed which includes a housing having opposed similar housing halves with pipe nipples extending therefrom and with resilient sleeve units installed on respective lock rings mounted in recessed portions of the housing halves. The sleeves act to compressibly engage each other in the valve open condition and engage opposite sides of the gate in the valve closed condition. Each sleeve unit has a radially outwardly extending flange on the inner and outer axial ends with these flanges being located in indented regions between each lock ring and the respective housing half. An encircling thin stiffening ring of harder material is bonded to the axially outer surface of the flange on the inner end of each sleeve, each stiffening ring being shaped with a right angle bend so as to provide both axially and radially facing surfaces for each sleeve body. Each stiffening ring is engaged with the respective lock ring along the entire length of the stiffening ring.

Abstract: A packingless gate valve is disclosed which includes a housing having opposed similar housing halves with resilient sleeve units which compressibly engage each other in the valve open condition and engage opposite sides of the gate in the valve closed condition. Each sleeve unit has a flange on the inner and outer axial ends, with the flanges extending radially outwardly from the sleeve body. An encircling thin stiffening ring of harder material is bonded to the axially outer surface of the flange on the inner end of each sleeve, each stiffening ring being shaped with a right angle bend so as to provide both axially and radially facing surfaces for each sleeve body. The particular configuration and position of the stiffener rings has been found to function advantageously in preventing the pliable sleeve material from following the gate as it penetrates between the opposed sleeve units.