J48Z & P

The J48 is supplied in two special versions, J48Z Zero Regulator and the J48P Proportionator. Both include the quick release spring adjustment mechanism providing easy access for spring adjustment and maintenance.
The J48Z Zero Regulator is utilised where burner train design creates a negative pressure on the downstream side of the regulator. In this situation, very low outlet pressures -0.75 to +0.25mb (-0.3 to +0.1"wg) are required. To accuracy maintain these very low pressures a large diaphragm and low rate spring are incorporated. A Jeavons J48 regulator, set at 5 - 10mb,  should preceed the J48Z.
The J48P Proportionator controls gas pressure in a burner train, relative to the air supply. This ensures that the air / gas ratio stays in proportion for various flow conditions. The J48P can be top loaded from an external source such as the air supply.
Both versions, which are designed for natural, liquefied petroleum and manufactured gases, must be installed in horizontal pipelines.