ASME B73.1-2001 pdf free download.SPECIFICATION FOR HORIZONTAL END SUCTION CENTRIFUGAL PUMPS FOR CHEMICAL PROCESS
The seal chamber shall be designed to incorporate the details quantified in Figs. 5 and 6.
The secondary seal contact surface(s) shall not exceed a roughness of 63 in. (1.6 ?m).
Seal chamber bore corners and entry holes, such as those used for flushing or venting, shall be suitably chamfered or rounded to prevent damage to secondary seals at assembly.
The seal chamber shall include means of eliminating trapped air or gas. Vent connections, when required for this purpose, shall be located at the highest practical point; drains, when provided, shall be located at the lowest practical point.
The location of piping connec- tions to the seal chamber for other functions is optional. Cartridge seals may center on the shaft and not pilot on the seal chamber. Pumps equipped with seal chambers experience in- creased process fluid velocity in the seal chamber and mechanical seal gland area.
Any particles in the process fluid, including fluids described as clear that have incidental particles, can collect in this area and cause erosion. Contact the pump manufacturer for solutions that extend the life of the seal chamber and mechanical seal gland. The size of all piping connections to the seal and seal gland shall be 1 ⁄ 4 in. NPT min. with 1 ⁄ 2 in.
NPT preferred.
4.6.3 Seal Chamber Runout. Mechanical seal performance is highly dependent on the runout condi- tions that exist at the mechanical seal chamber. Pump shall be designed for compliance with the runout limits shown below.
On smaller sizes, the actual measurement of these runout values may not be possible or practical on an assembled pump.
Types of runout having signifi- cant effect on seal performance include:
(a) Seal Chamber Face Runout. This is a measure of the squareness of the seal chamber face with respect o the pump shaft. It is measured by mounting a dial indicator on the pump shaft and measuring FIM at the face of the seal chamber. The maximum allowable runout is 0.003 in. (0.08 mm) FIM (see Fig. 8).
(b) Seal Chamber Register Runout. Provisions shall be made for centering the gland with either an inside or outside diameter register. This register shall be concentric with the shaft or sleeve within 0.005 in. (0.13 mm) FIM (see Fig. 9).
4.6.4 Stuffing Box. The stuffing box packing bore surface shall not exceed a roughness of 63 ?in. (1.6 ?m). One lantern ring connection shall be provided.
A second connection and the location of piping connec- tions to the stuffing box and gland are optional. The size shall be 1 ⁄ 4 in. NPT min., with 1 ⁄ 2 in. NPT preferred. Registers shall maintain the stuffing box bore concentric with the axis of the pump shaft within 0.005 in. (0.13 mm) FIM and the stuffing box face perpendicular to the axis of the assembled pump shaft within 0.003 in. (0.08 mm) FIM. Figure 7 shows the recommended stuffing box dimensions. The box also shall be suitable for proper installation and operation of mechanical seals, including means of eliminating trapped air or gas at the highest practi- cal point.
4.6.5 Space Requirements
4.6.5.1 Space in the various seal chamber designs shall provide for one or more of the following configu- rations of cartridge or noncartridge seals:
(a) single inside mechanical seal, balanced or unbal- anced, with or without a throat bushing, and with or without a throttle bushing
(b) double seal, balanced or unbalanced inboard and outboard
(c) outside mechanical seal, balanced or unbalanced, with or without a throat bushing
(d) tandem seals, either balanced or unbalanced
(e) gas seals.ASME B73.1 pdf download.ASME B73.1-2001 pdf free download
