Type L Series low-pressure diaphragm seals feature removable, elastomer diaphragms that may be replaced or repaired if required. These seal elements are intended for low-pressure sensitivity instruments such as bellows and diaphragm type gauges. They are sensitive to pressure changes as low as 2” H2O (51 mm H2O at 4°C).
Type L Series diaphragm seals employ diaphragms retained between two bolted members. In the clean-out design, the diaphragms are situated between the top and middle ring. In the LB and LG design, the diaphragms are located between the top and bottom. The diaphragm is loosely retained in the upper housing for easy repair or replacement. This extends the life of the seal element and allows for field replacement and service.
Threaded Seal Eléments
There are four basic versions of L Sériés diaphragm seals with threaded attachments. The LB seal element is used for pressure applications only and has a pressure rating of 1250 psig at 100°F (86 bar at 38°C). The LG seal element is similar to the LB seal, except that it has a 1/4 NPT flushing connection. The LA seal element has a standard pressure rating of 1250 psig at 100°F (86 bar at 38°C), but may also be supplied with a pressure rating of up to 5000 psig. The LH seal element is similar to the LA seal element except that it features a 1/4 NPT flushing connection. Both hâve an extended area albwing for négative displacement making them idéal for vacuum applications.
Flanged Seal Eléments
There are two basic versions of flanged L Sériés seal éléments. The flange is a standard raised face style.