Type 6358, 6365, & 6365C
Fisher Controls
Instruction Manual
Type 6358, 6365, & 6365C Relief Pilots
December 1986
Form 5211
Introduction
Scope of this Manual This instruction manual includes installation maintenance, and parts information for the Type 6358, 6365, and 6365C relief pilots. For installation and operation of a complete relief valve assembly, refer to separate manuals (such as the one for a Type 63EG, 289P, 1805P, or 1808 relief valve).
Description
W3716
TYPE 6358 RELIEF PILOT MOUNTED ON TYPE 1808 MAIN VALVE
A single Type 6358 or 6365 pilot is used on the main valve body of a relief valve as shown in figure 1. A Type 6365C cascade pilot is used along with a Type 6365 pilot to reduce the buildup required for the main valve to go wide open. The Type 6358 pilot bleeds only when the main valve is stroking open. The Type 6365 and 6365C pilots bleed only when the main valve inlet pressure is above the Type 6365 set pressure. These pilots have unbalanced plugs and can be used in both liquid and gas service.
Specifications Table 1 lists specifications for various Type 6358, 6365, and 6365C pilot constructions. For each pilot (except the Type 6358 pilot, which has a plugged restriction), the restriction diameter is indicated by a letter stamped on the bottom of the pilot body next to the tapped side outlet. The pilot spring range appears on the pilot spring case.
W3709
TYPE 6365 RELIEF PILOT MOUNTED ON TYPE 63EG MAIN VALVE
Figure 1. Typical Relief Pilot Constructions
ŠFisher Controls International, Inc., 1983, 1986; All Rights Reserved