Diaphragm Seals

Diaphragm seals are isolation devices, designed to separate pressure gauges and other instruments from the process media while allowing the instrument to accurately measure pressure. Marsh Bellofram recommends the use of diaphragm seals to extend instrumentation service life and reduce downtime and maintenance costs, by protecting instrumentation from corrosion, clogging, freezing, or pulsation damage.

Model B8498 Gauge Protector

The Marsh Bellofram model B8498 gauge protector is expressly designed for use in extremely high-volume displacement applications, such as those found among gauges operating at pressures up to 200 psi, as well as within vacuum applications. Gauge protectors are available in 1⁄4" threaded connections and with chrome plated zinc construction. A 3⁄8" flush plug is standard in the process side housing. Units are filled and calibrated to gauges only.

Model 12000 Serviceable Mini Dia Seal

The Marsh Bellofram model 12000 serviceable mini diaphragm seal is designed for use with gauges and instruments operating at pressures of 2500 psi with stainless steel models and 500 psi with PVC models. Marsh Bellofram recommends the use of diaphragm seals such as the model 12000 to extend instrumentation service life and reduce downtime and maintenance costs.

Model 13000 Mini Welded Diaphragm Seal

The Marsh Bellofram model 13000 mini all-welded diaphragm seal is designed for use with 2” to 3.5” bourdon tube gauges with a minimum pressure of 100 psi. Seals are available in all 316 stainless steel or with Hastelloy™ C process housing and diaphragm. Maximum operating pressure is 2000 psi at +100°F.

Model 13040 All-Welded Diaphragm Seal

The Marsh Bellofram model 13040 all-welded diaphragm seal is designed for use with 2” to 4.5” bourdon tube gauges with pressure ranges from vacuum to 1000 psi. Seals are available in all 316 stainless steel or with Hastelloy™ C process housing and diaphragm.

Model 14000 Removable Diaphragm Seal

The Marsh Bellofram model 14000 removable diaphragm seal features a clamped metal design with interlocking construction inside of the bolt circle for perfect alignment. The upper and lower housings clamp the diaphragm in place and allow for ease of field servicing. The model 14000 is available in threaded connections for pressures from vacuum to 2500 psi.

Model 14040 Welded Diaphragm Seal

The Marsh Bellofram model 14040 is a welded diaphragm seal, offering a special diaphragm-to-upper design that allows the upper housing to be removed with the instrument still in place, without losing liquid fill. The same interlocking feature as the 14000 is used in the model 14040 to ensure precise alignment of the upper to the lower housing. Units are available in threaded connections for pressures ranging from vacuum to 2500 psi. Fill/bleed port screw in the upper housing is standard with an optional flush connection also available.