Stuffing boxes

Stuffing box pocking Stuffing box follower Bor-nut to tighten stuffing box... 

Stuffing box tightened from outside here with ongle screwdriver... 

Shaft Sleeve. Renewable hook-type shaft sleeve that extends through the stuffing box and gland shall he provided. Shaft sleeve shall he (316 stainless steel), ( 20 stainless steel) or (XH-800 Ni-chrome-horon coated 316 stainless steel with coated surface hardness of approximately 800 Brinnell). 

Stuffing Box. Stuffing box shall he suitable for packing, single (inside or outside) or double-inside mechanical seal without modifications. Stuffing box shall he accurately centered by machined rabbit fits on case and frame adapter. 

Stuffing Box with Mechanical Seal. Mechanical seal shall he of the (single inside) (single outside) (double inside) (cartridge) type and (balanced) (unbalanced). 

Luhtication—Stuffing Box with Mechanical Seals. Suitable tapped connections shall he provided to effectively lubricate, cool, flush, quench, etc., as required by the application or recommendations of the mechanical seal manufacturer. 

Modifications Requited, Temperature Range 250-350°F. Pumps for operation in this range shall he provided with a water-jacketed stuffing box. 

Cast Iron—316 SS Fitted. IS" only pump shall have cast iron casing and stuffing box cover. 316 SS metal impeller shaft shall he 1045 steel with 316 SS sleeve. 

FIG. 10-98 Soft packing in an auxiliary stuffing box for handling gases,... 

Application of Packing Coils and spirals are cut to form closed or nearly closed rings in the stuffing box. Clearance between ends should be sufficient to allow for fitting and possible expansion due to increased temperature or hquid absorption of the packiug while in operation. 

Pre.s.sure. Pressure affects the choice of material and whether balanced or unbalanced seal design can be used. Most unbalanced seals are good up to 100 psig stuffing box pressure. Over 100 psig, balanced seals should be used. 

External seals (Fig. 10-115) are installed with all seal components protected from the process fluid. The advantages of this arrangement are that (1) fewer critical materials of construction are required, (2) installation and setting are somewhat simpler because of the exposed position of the parts, and (3) stuffing-box size is not a hmiting factor. Hydraulic balancing is accomphshed by proper proportioning of the seal face and secondary seal diameters. 

Throttle bushings (Fig. 10-117) are commonly used with single internal or external seals when sohds are present in the fluid and the inflow of a flushing fluid is not objectionable. These close-clearance bushings are intended to serve as flow restric tions through which the maintenance of a small inward flow of flushing fluid prevents the entrance of a process fluid into the stuffing box. 

Air vent-Doub/e Spiro agitator — Stuffing box-Outboard bearing ... 

The power P is only that imparted to the liquid by tbe impeller. It is not tbat delivered to tbe motor drive, which additionally includes losses in the motor and speed-reducing gear. These may total 30 to 40 percent of P A stuffing box where tbe shaft enters a covered vessel causes additional losses. 

This is the pressure measured in the stuffing box or seal chamber. This is the pressure to be sealed by the mechanical seal or packing. The seal chamber pressure must be within the limits of the mechanical seal. This... 

The holes reduee stuffing box pressures and balanee axial loading. 

The shaft under the restriction bushing at the bottom of the stuffing box or seal chamber. 

Oil, water, grease, or any liquid or substance compatible with the tluid are forced under pressure into the paeking through the lantern ring by means of a connection on the stuffing box wall to provide these three hinetions. 

Permit the pump and paeking to leak generously for about 15 minutes to allow the packings to absorb the pumped fluid,. swell, seat and adjust to the stuffing box wall and the shah. 

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