Comparación entre los sustantivos transparentes

There are generally three methods used for joining cast iron soil pipe. Hub and spigot cast iron soil pipe may be joined by compression gasket or caulked joint. Hubless cast iron soil pipe is joined by using a no-hub coupling.

Compression Gaskets

The compression gasket is a precision-molded, one-piece gasket that is made of an elastomer that meets the requirements of ASTM C-564. The physical characteristics of this elastomer ensure that

Figure 1—Steel Pipe Cutter. Figure 2—Cutting Pipe With Snap Cutter.

the gasket will not decay or deteriorate from contact with the materials flowing in the pipe or chemi-icals in the soil or air around the pipe. The compression joint is made as follows: (1) Clean the hub and spigot so they are reasonably free from dirt, mud, sand, gravel, and other foreign materials.

When installing pipe that has been cut, make sure the sharp edge is removed. The sharp edge may jam against the gasket’s seals, making joining very difficult. The sharp edge may be removed by filing or tapping the edge with a ball-peen hammer (2) Fold and insert the gasket completely into the hub. Only the flange that contains the identification information remains exposed on the outside of the hub. (3) Lubricate the joint following the manufacturer’s recommendations. Sizes 2″ through 15″ may be lubricated using a manufacturer’s recommended lubricant. Some manufacturers recommend using an adhesive lubricant on large-diameter pipe and fittings (5″−15″). It should be noted that use of adhesive lubricant does not take the place of proper join restraint when required. (4) Align the pipe so that it is straight. Using the tool of your choice, such as the puller depicted in Figure 4, push or pull the spigot through all of the sealing rings of the gasket. You will feel the spigot end of the pipe bottom out in the hub. Fittings may be installed by using the tool of your choice or by driving the fitting home by using a lead maul. To do this, strike the fitting on the driving lug or across the full hub. Hit it as hard as necessary, the lead will deform without harming the fitting.

Using the lead maul is the fastest and easiest way to install fittings on hub and spigot cast iron soil pipe. Proper safety procedures should be observed in making the joint.

Figure 4—Pulling Assembly.

Figure 3—Compression Gasket Joint.

couplings are available. The following outlines the installation procedures of no-hub couplings that meet the requirements of CISPI 310. It must be noted that these installation procedures are not intended to be applicable for couplings other than those manufactured in accordance with CISPI 310.

(See Figure 5.) These couplings are manufactured using a stainless-steel shield-and-clamp assembly and an elastomeric sealing sleeve conforming to he requirements of ASTM C-564. The following steps should be taken to ensure a proper joint: (1) Place the gasket on the end of one pipe or fitting and the stainless steel clamp-and-shield assembly on the end of the other pipe or fitting.¹(2) Firmly seat the pipe or fitting ends against the integrally molded center stop inside the elastomeric sealing sleeve. (3) Slide the stainless steel shield-and-clamp assembly into position over the gasket and tighten the bands. The bands should be tightened using a calibrated torque wrench set at 60 in./lbs. For larger diameter couplings that have four bands, the inner bands should be tightened first and then the outer bands tightened. In all cases, when tightening bands, they should be tightened alternately to ensure that the cou-pling shield is drawn up uniformly.

Caulked Joints

Oakum is made from a vegetable fiber and is used for packing hub and spigot joints. Cotton and hemp also can be used. These materials are usually twisted loosely into strands or braided and formed into a circular or rectangular cross section. A rough rule-of-thumb method for estimating oakum requirements is to take 10 percent of the weight of the lead required for caulking. Table 1 provides a more accurate method for estimating oakum requirements.

Lead quantities can be roughly estimated by rule of-of-thumb as 12 ounces per inch of diame-ter as a minimum. Thus, a four-inch diamediame-ter pipe would require three pounds of lead as a minimum.

An eight-inch diameter pipe would require six pounds of lead. This allows for skimming-off and for a reasonable loss due to spillage in pouring. Table 2 lists suggested lead quantities for various pipe and fitting diameters. The amounts shown apply only to cast iron soil pipe and fittings made accord-ing to ASTM Standard A-74.

Figure 5—CISPI 310 CI No-Hub^®coupling.

1The use of adhesive lubricants is permissible as recommended by the manufacturer. When adhesive lubricants are used, wait 24 hours before testing. The use of the adhesive lubricant does not take the place of proper joint restraint.

The standards of the Lead Industries Association contain the specification for lead quality. Lead for caulking purposes should contain no less than 99.73 percent of lead and no more than the following maximum allowable impurities: .08 percent copper, .002 percent zinc, .002 percent iron, .25 per cent bismuth, .02 percent silver, and a total of not more than 0.15 percent arsenic, antimony, and tin. The melting point for caulking lead is 621^o F, and the proper pouring temperature is 790^o–830^oF. The lead is ready for pouring when it becomes a cherry red. After cooling, there is a shrinkage of approximately 5.8 percent from the liquid state.

Prior to the late 1950s, the caulked joint was the only method of joining hub and spigot cast iron soil pipe. To make a caulked joint, the following steps are used:

TABLE 2

Lead Required to Caulk Cast Iron Soil Pipe Joints

Service Extra heavy

SV XH

Pipe Size Lead Ring

in Inches Depth Inches Cu. Ins. Wt. Lbs. Cu. Ins. Wt. Lbs.

2 1 2.81 1.15 2.91 1.19

3 1 3.90 1.6 4.17 1.71

4 1 4.98 2.04 5.25 2.15

5 1 6.06 2.49 6.24 2.56

6 1 7.15 2.93 7.42 3.04

8 1.25 15.06 6.17 15.49 6.35

10 1.25 18.90 7.75 19.34 7.93

12 1.25 25.53 10.47 26.02 10.67

15 1.5 43.09 17.67 43.38 17.8

TABLE 1

Quantity of Oakum Packing Required Per Joint in Standard Hub and Spigot Cast Iron Soil Pipe

Tarred or Untarred Dry Unoiled Sq. Braided

(Oiled) Twisted Oakum Oakum Packing

Pipe Size Twisted Oakum Packing Pounds Pounds (Approx.)

in Inches Packing, Pounds (Approx.) Using I ring

2 .14 .09 .07

3 .16 .10 .08

4 .18 .13 .10

5 .20 .15 .12

6 .21 .16 .13

8 .44 .33 .17

10 .53 .40 .20

12 .61 .46 .24

15 .94 .71 .45

Table 2. (3) Molten lead is then poured into the joint. The molten lead is brought up to the top of the hub.

(4) After the lead has solidified and cooled somewhat, the joint is ready to be caulked. Caulking is per-formed with inside and outside caulking irons. Caulking the joint sets the lead and makes a leak-free joint.

Any time caulked joints are used, safety procedures should be observed and protective equip-ment and clothing should be worn. Use customary precautions in using or handling molten lead. If a horizontal joint is to be made, a pouring rope must be used to retain the molten lead in the hub.

Note: The caulked joint is a very time-consuming method of joining cast iron soil pipe. The vast majority of all hub and spigot cast iron soil pipe installed today is joined by using the compression gasket.