Before starting any installation, take some time to make sure your job has been designed properly.

There are many factors that come into play when designing a system. If one item is overlooked or miscalculated it can cause hundreds or even thousands of dollars in repair costs down the road.

Many times an item that works flawlessly by itself is installed into a system with many other parts and because of unforeseen variables creates a negative synergy.

It costs too much money to over build a system because of inadequate design or to not have the system work as planned because proper hydraulic principles were not taken into consideration in the design.

Make sure you have taken into consideration general design principles like friction loss, water velocity, adequate pump horsepower, air evacuation (pressure relief valves and air relief valves), elevation, grade changes and temperature changes. It saves so much time, money and resources to do the job right the first time.

Have an Engineer or an I.A. Certified Designer plan the job or check your design. Your local S.C.S. office can be an excellent resource for assistance in checking a system design.

Just like working with your family doctor, it doesn't hurt to get a second opinion. It will be well worth it in the long run.

The following section of this manual is designed to be an overview of the installation process when working with PVC pipe and fittings. Most of the installation steps have a reference to a later section in this manual which gives more information on that particular step.

INSTALLATION STEPS

NACO products are manufactured to the highest quality control standards in the industry. Fittings are randomly pulled from production batches and run through several tests to assure consistent reliability. Each fitting is hand inspected by our quality control craftsmen before leaving the plant.  

However, during the shipping and handling process, human errors can and do occur, resulting in shortages or damage to the fittings.

In very cold weather PVC becomes stiff and loses much of its impact resistance. Just remember when the temperature falls handle the fittings gently. Don't drop fittings from warehouse shelves or truckbeds. Don't throw fittings from the back of trucks into or along side trenches. When using gasketed fittings, installation will be much easier if the fittings, with their gaskets, have been allowed to come up to a minimum temperature of 50 degrees Fahrenheit.

Never install outlets such as risers or nipples in fittings on the ground prior to installation. These can make great levers when straightening or positioning a fitting, unfortunately, they may also cause the fitting to fracture. Use a chain wrench or other suitable positioning device when installing and aligning the fittings in the line.

EXCAVATING THE TRENCH

PRE ASSEMBLY

In the event that the pipe needs to be cut for length, it is essential to insure a proper assembly, that a square cut is achieved on the pipe end.  It is best to make a mark around the entire circumference of the pipe before cutting.

Use the bevel from a factory made fitting or pipe end as a guide to determine the angle and length of taper when beveling a pipe end.

The end may be beveled using a portable sander or grinder with an abrasive disk or by using a beveling tool, hand rasp or disk cutter.

After the pipe has been cut, re-mark the insertion mark on the end of the pipe before installation.

1. Clean the bell end of the fitting and gasket material making sure there is no foreign material on either surface.
   
   
2. Make sure the spigot end of the fitting or pipe is clean by wiping it off with a clean, dry rag or cloth from the end of the spigot to a length at least one inch longer than the bell of the fitting it will be inserted into.
   
   
3. Apply a thin coating of lubricant, supplied by the pipe manufacturer, around the entire circumference of the spigot end.  The coating should be the equivalent of a brush coating of enamel paint and can be applied by hand, cloth, pad, sponge, glove or paint brush.  Do not allow the spigot end to touch the ground after the lubricant has been applied.  Contamination can damage the gasket or cause the gasket to roll out of the gasket pocket.
   
   
4. Brace the bell end before inserting the spigot into the bell to prevent previously installed joints from closing up.
   
   
5. Position the bevel of the spigot so it is resting against the gasket inside the gasket pocket.  Push the spigot into the gasket pocket until the insertion mark on the spigot end of the pipe lines up with the edge of the belled end of the pipe.

DO NOT OVER INSERT THE SPIGOT INTO THE GASKET POCKET!

The assembly can be made by hand when using smaller diameters of pipe by twisting the spigot slightly as it enters the bell.  Other assembly methods include using a bar and block, lever pullers or hydraulic jacks.  Backhoe buckets are not recommended for installing gasketed fittings, even in large diameter sizes.

Generally, the backhoe operator cannot see the insertion mark on the spigot end and cannot feel when the spigot bottoms out in the gasket pocket.  This is the cause of many broken pipes and fittings.

When using mechanical force to install joints, place a wooden block or plank over the end opposite the spigot to prevent damage to the fitting or the pipe end.

CAUTION!  DO NOT OVER INSERT THE JOINT!  When the spigot is inserted beyond the insertion mark, the chamfered end of the spigot acts like a wedge in wood, expanding out the bottom or tapered end of the gasket pocket and causing the pipe or fitting to split.

It is necessary to have a gap between the end of the spigot and the end of the gasket pocket.  This gap will allow for Thermal Expansion and Contraction of the pipe as it heats and cools during normal operation.

If there is no insertion mark on the pipe spigot or if the pipe has been cut and beveled an insertion mark must be placed on the spigot end.

To determine the correct position of the insertion mark, measure the length of the gasket pocket or bell end of the pipe or fitting.  Subtract a minimum of 3/4 inch from this measurement, as explained in the Thermal Expansion section.  Place a mark on the spigot to correlate with the adjusted measurement.

CAUTION! Depths of gasket pockets or bell ends may vary with pipe manufacturers.  Especially when using PIP pipe.  The general rule for large diameter pipe is the length of the gasket pocket should be half of the diameter of the pipe.  ALWAYS double-check the insertion mark on the pipe to make sure it is the proper length for the fittings when starting a job.

A quick way to check the insertion mark is to lay the fitting next to the spigot end of the pipe.  When the end of the fitting lines up with the insertion mark on the pipe, the spigot end of the pipe should be approximately 3/4 inch back from the end of the gasket pocket on the fitting.

RECOMMENDED GASKET LUBRICANT JOINTS PER QUART
SIZE	JOINT	SIZE	JOINT	SIZE	JOINT
3"	100	10"	35	21"	10
4"	85	12"	25	24"	9
6"	60	15"	15	27"	8
7"	45	18"	12	30"	7

OBJECTIVE:

1. Cut the pipe as square as possible to ensure a proper fit.  It is a good idea to mark the pipe all the way around before cutting.
   
   
2. Remove the burrs and the sharp edges from the cut end of the pipe with a knife, file, reamer or de-burring tool.  It is best on large diameter pipe to round the outside edge of the pipe giving it a slight chamfer.  Burrs or sharp edges left on the cut end of the pipe can create grooves or cause hang-ups in softened plastic.
   
   



3. Wipe both surfaces to be cemented with a clean rag removing all dirt and moisture.  Dirt and other foreign material can prevent adhesion and cause an inadequate chemical weld.
   
   
   
   
4. Place the fitting on the Pipe without any cement or primer and check the dry fit.  The pipe should be able to slide part way into the fitting and should not be loose or sloppy.

ASSEMBLY:

PRIMING

1. Apply a liberal coat of primer to the bell end of the fitting.  Make sure the primer has evenly coated the surface of the fitting both top and bottom.  Keep the surface of the fitting wet with primer until it starts to soften.  Softening times will vary with weather conditions.  Additional coats of primer may be needed to achieve softening.  More time is required in cold weather.  Remove any puddles of primer when proper penetration is made.  If extra primer is left in the fitting it will over soften the material and reduce the strength of the plastic.
   
   It is recommended that a colored primer be used such as Valor V700, or equal, purple primer.



2. Apply primer to the spigot end of the pipe to a length equal to the depth of the bell on the fitting.  The application should be made in the same manner as the bell end of the fitting in step 1.
   
   
3. Double check the bell end of the fitting and the spigot end of the pipe for proper softening.  In some cases a second coat of primer is required.

1. As soon as the plastic has been softened with the primer and while the surface is still wet, apply a medium layer of cement inside the bell end of the fitting.  Remove any puddles of cement.  Do not apply cement any deeper than the end of the bell.  Do not allow the cement to run down the pipe or fitting.



2. Quickly apply a full even layer of cement to the spigot end of the pipe which has been softened with the primer.  Take care not to brush out the cement like paint.  Flow the cement around the pipe with the appropriate size applicator.  Spread the cement around the pipe up to a length equal to the bell of the fitting.
   
   
3. A second coat of cement on the pipe may be required when using large diameters.  Sufficient cement is required to fill any gap in the joint.
   
   
4. Immediately assemble the pipe and the fitting. If possible twist the pipe 1/8 to 1/4 turn as you insert it.

   

   
   
5. Hold the joint together for a short time (usually around 30 seconds) until the pipe quits trying to push away from the fitting joint.
   
   
6. Check the bead of cement around the fitting.  The bead should be full with no voids or gaps.  If gaps are present in the cement there was not enough cement applied to the joint and the joint may be defective.
   
   
7. Wipe off excess cement with a rag.  If excess cement is left on the pipe it can cause over softening of the pipe. After the joint has been properly made and it starts to set up, the active agent in the cement dissipates out of the joint leaving behing two plastic surfaces which have been chemically bonded.

PRIMERS & CLEANERS

COLD WEATHER

When cold weather joints become unavoidable, good joints can still be made by using a few precautions.

In cold weather, solvents penetrate and soften the PVC surfaces slower than in warm weather. Also, the plastic becomes more resistant to the penetration process of the primer and cement. Therefore it becomes more important to pre-soften the plastic surfaces with a good quality primer. Also, because of slower evaporation during cold weather, the cure time will slow down dramatically.

Tips for cold weather cementing:

1. Prefabricate as much of the system as possible in a heated work area.
2. Store your cements and primers in a warm area when you are not using them and make sure they remain fluid.
3. Remove all moisture including ice and snow. Do not allow moisture to enter your cement or primer cans. This will contaminate the mixture and may cause the joints to fail.
4. Use a qood quality primer such as Valor V-700 or equal to soften the plastic. More than one application may be needed.
5. Allow a longer cure time before the system is used and remove excess cement.

A good quality cement and primer will make successful joints in temperatures as low as -15° Fahrenheit without any additives and with proper attention during installation.

HOT WEATHER

When making solvent weld joints, you must remember that the softening agents in the primer and the cement dissipate out as the joint cures. In hot temperatures this dissipation occurs more rapidly, possibly before you have the joint assembled properly.

Heat also speeds up the softening process. If puddles are allowed to sit, they can over soften the plastic and go right through the pipe, or fittings.

Tips for hot weather cementing:

1. Store cements and primers in a cool or shaded area.
2. Use heavier, higher viscosity cement, as it will provide more open time after application and before insertion.
3. If possible, store the fitting and the end of the pipe to be cemented in the shade until the joint is assembled.
4. Cool the surfaces to be joined by wiping with a cool damp rag. Make sure the plastic is dry before applying the primer and cement.
5. Try to make your solvent weld joints in the cooler morning hours.
6. Make sure the cement on both pieces being joined is still wet and has not formed a "skin" over the top. If skinning has occurred you can try applying a thin coat of primer over the cement to reactivate it. With large diameter pipe and fittings, more help may be required to get the joints together before skinning occurs.

Teflon tape, when compressed between male and female threads in plastic fittings and joints, can cause deformation, leading to leakage and, possibly, to cracked fittings.

Sealant, when compressed between threads, flows outward to achieve an effective seal against leakage.

We recommend the use of a teflon paste made for plastic fittings such as Lasco "Blue Pipe Thread Sealant" or IPS Weld On "Seal-On 500" teflon paste for plastic fittings.  The use of a teflon paste not specifically made for plastic could cause deterioration and destroy the fitting.

INSTALLING SADDLES ON PVC PIPE

1. Heavy-duty power drill with hole saw attachment and generator.
   
   
2. Two pre-cut steel bands per saddle; 5" to 10" longer than the circumference of the pipe.
   
   
3. Two steel strapping tensioners and one crimper.
   
   
4. Valor V700, or equal, colored primer and Valor PVC-919, or equal, solvent cement and applicators.

1. Once the lateral is assembled and cemented, mark the placements where the saddles are to be installed with a felt marker. Be sure to note the temperature when these are marked. The effects of temperature change can lengthen and shorten a PVC line by as much as 2 inches per 100 feet.
   
   
2. Place two steel strapping bands, one on each side of the drilled hole, and take up most of the slack with the tensioning tools. The straps should be loose enough to easily slip over the saddle. We strongly recommend the use of steel strapping and the proper tools. Even though the initial tool costs are higher, the time they save will easily recover the investment in a couple of jobs, or in one repair job that you don't have to perform. If the steel tools are out of the question, we then recommend stainless steel "ideal clamps". Although they are not as fast, they do an adequate job. We do not recommend the use of plastic banding. Plastic cannot be tightened down satisfactorily without breaking.
   
   
3. Clean both the saddle and the pipe surface with a dry cloth; then prime with primer and a large cotton swab or roller.
   
   
4. Apply a thick layer of Valor 919 or IPS Weld On 719 cement to both surfaces. If you can see white pipe through the glue layer, it is too thin. We suggest using a large cotton swab or a roller for this application. Use plenty of cement; it is less expensive than a repair.
   
   
5. While one man holds the saddle in place, the second man slides the steel strapping over the two ends of the saddle and quickly cinches them down. The bands should be positioned halfway between the edge of the saddle and the riser to prevent buckling of the fitting. Note that the second man is using two tensioners, one on each band. He tightens them both, one at a time, using one hand. Excessive pressure with both hands can strip the mechanism and cause unnecessary wear on the tools. He then crimps the bands. Elapsed time from priming to installed and tightened should be about 50 to 60 seconds.
   
   
6. You should now be ready to move onto the next saddle installation.

NOTE:

See the solvent weld joints section for more information on the proper use of primers and cements. The same rules that apply to primers and cements in solvent weld joints apply to installing saddles. Wipe off any excessive primer or cement that has dripped down the side of the pipe. These drips can puddle at the bottom of the pipe and continue to soften the plastic creating a weak spot or hole in the pipe.

Imagine a freight train speeding along a railroad track pulling fifty rail cars loaded with freight.  Now imagine trying to make that train follow a sharp 90° bend you have placed in the track just ahead.

Water flowing through a pipe under pressure, like the train, develops a tremendous amount of force.  In very large diameter pipe it can exceed 100,000 pounds force at 100 PSI.

AREAS TO PLACE THRUST BLOCKS

1. CHANGES IN DIRECTION such as elbows and tees.  The amount of force developed increases with the angle of deflection.  The amount of the internal pressure, plus the force created by the direction change, must be restrained.



2. CHANGES IN SIZE when reducers are placed in line.  The larger the reduction the more force developed.
   
   
3. VALVES.  All valves regardless of the type, size, or frequency of use should be anchored.

MAKING A THRUST BLOCK

At each of the above points where thrust force will develop, a thrust block poured from concrete needs to be installed. Run the concrete on the opposite side of the water flow. The concrete should go from the fitting back to the natural, undisturbed trench wall. It is best to hand dig the area for the thrust block to provide maximum holding power. A form for the thrust block can be made using cardboard boxes or a wooden frame. Pour a mix of one part cement, two parts washed sand, and five parts washed gravel. The pipe and the fitting should be wrapped with builders felt where it will contact the concrete to prevent wear caused from vibration.

THE SIZE OF THE THRUST BLOCK

The size of the thrust block is determined by the thrust force in pounds divided by the bearing strength of the soil.

BEARING STRENGTH OF SOILS

Initial Backfill

Plastic, with its ability to be flexible, resist corrosion and rusting, and the ability to be solvent cemented in the field make it an ideal material for the construction of pipe.

Air trapped in the line reduces the capacity of the pipe to carry water.  An air pocket trapped in a high point of the line is the equivalent of installing a reducer in the line.  As this restriction becomes larger the pump needs to work harder to maintain the desired volume in the line.

Water is almost incompressible compared to air.  Compressed air in lines can reach pressures far in excess of the static pressure of the line.  As the pump is increased to compensate for the loss in volume caused by the restriction from the trapped air pocket, the air is compressed even more becoming a greater threat to the system.

As compressed air exits the system, the water flowing behind the air closes the air relief valve.  If the air is evacuated too fast, the water can create water hammer surges great enough to rupture the pipe as it runs into the air relief valve and comes to a sudden stop.

SOURCES OF AIR ENTRAPMENT

Pressure relief valves are just as important to your water system as brakes are to your car.

To achieve a basic understanding of water hammer let's take a look at a typical example, illustrated below.

In our example, we have a reservoir of water. Toward the bottom of the reservoir there is a PVC pipe taking water out to our irrigation lines. Several feet down the line there is a shutoff valve.

When the valve is open, the elevation head (weight of the water in the reservoir) forces water through the outlet pipe and out of the reservoir. We now have a constant velocity of water running through the pipe. Generally, systems using PVC pipe should be designed with a maximum of 5.5 second feet of water flow.

When the valve is suddenly closed, the water flowing through the pipe slams into the valve. This is like trying to stop a freight train on a dime. The forward momentum of the water is re-directed outward forcing the pipe to expand under increased pressure. As soon as the first layer of water is re-directed, the process is continued with the next layer. The water upstream, flowing down from the reservoir, continues to flow at the same speed until the re-directed layers of water work themselves back to the reservoir.

The high pressure (water hammer) moves upstream like a wave of the sea. The water in front of it is still flowing down towards the valve as before.The water behind it has been brought to rest but is still exerting outward pressure on the pipe.

Eventually, the high pressure wave reaches the reservoir and has stopped all movement of water down the pipeline towards the valve.  When the energy is released from the re-directed water in the pipe, the water moves toward the reservoir and away from the valve.  Since the valve is still shut, a vacuum is created in the pipeline.  This, together with the elevation head in the reservoir, causes another wave of water to flow down the pipe and slam into the valve.

This process continues at predictable intervals until due to water friction and the elasticity of the pipe the waves are finally slowed to a complete stop.

CAUSES OF WATER HAMMER:

When a pipe contains a column of liquid, there is considerable kinetic energy stored in the liquid by virtue of its mass and velocity.  If the velocity is suddenly destroyed (by the quick closing of a valve or a cock) this energy cannot be absorbed, since the liquid is nearly incompressible and, therefore, appears as an instantaneous shock which may represent excessively high pressures.  This effect is greater as the pipe line is longer, the velocities higher, and the time closing the valve shorter.  Fairly long lines may contain enough mass of liquid to produce a water hammer of sufficient intensity to break pipe and fittings.  Quick closing valves, therefore, should be used only on short lines.

This nomograph may be used to predict the pressure surge that will result from given service conditions.  The chart may be used for any liquid.  Since the values given by the chart indicate only the pressure rise in the system, the value of the static pressure head must be added to the pressure rise to give the maximum pressures experienced in the system under the conditions involved.

HOW TO USE THE CHART:

1. Locate the desired water flow rate through the pipe on the velocity line.
   
   
2. Locate the length of pipe on the pipe length line.
   
   
3. Line up these points with a straight edge.
   
   
4. At the point of intersection on the pivot line, pivot the straight edge to the valve closure time line.
   
   
5. Read the pressure rise at the intersection of the pressure line.

EXAMPLE (see chart #1)

200 ft. pipe line: water flow at 3.5 ft. per sec., valve closure in 0.1 secs.; static pressure of 20 psi.

1) Line up 3.5 ft. per sec. with 200 ft.

2) Pivot about the pivot line to 0.1 sec.

3) Read 490 psi from the pressure line.

4) Add 20 psi to 490 to get 510 psi as the instantaneous pressure under the selected service conditions.

This chart is based on the Formula:

P =	.070×VL
	T

P =  Pressure rise (psi) above the static pressure.

V = Liquid velocity in the pipe (ft. per sec.)

L = Length of pipe ahead of the valve causing the hammer (ft.)

T = Time required to close the valve (sec.)

Chart #1

HOW TO USE THIS NOMOGRAPH:

2 PV- 160 (I. D. 2.193)
40 Gal. per Min Service

1) Line up these points with a straight-edge.
2) Read .95 (or 2.2 ft.) from the Head-Loss Line.
3) Read 3.49 Ft.  Per Sec. from the Velocity Line.

THE VALUES ON THIS GRAPH ARE BASED ON THE WILLIAMS AND HAZEN FORMULA: