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IrrigationRepair Tutorials and Forum

2016 Exam Schedule & Procedures
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DLM Instruction

2640 E. Parker Rd.
Muldoon, TX 78949

LI 3596

(832) 350-5809


How to Use the Sprinkler Design Service

1. To start the process you will need to fill out the following two forms from our website. One is for the sketch of your yard and the other one is for your technical and personal data:

  1. Graph Paper. Print the Graph Paper and draw your lot to one of the specified scales.
    Draw a plan of your property on the graph paper. Show all patios, decks, walkways, sheds, driveways, etc. Identify fences, walls and planters. Indicate like lawn, trees, shrubs, flowerbeds, and garden plots.
    Make sure you draw a square to show the location of the water meter or pump. Draw an X where you would like to locate your valve manifolds or leave the X off and we will place them in the best location to reduce labor and material costs. Draw a circle inside a building, near an electrical outlet, where you would like the timer located.
  2. Answer the following Questions Using the Info below under Getting Started:

    - Scale of drawing (1" = 10', 1" = 20', 1" = 30') Must draw plan to one of these scales.
    - Flow Test: ______________Gallons Per Minute.
    - Type of Sprinkler Pipe Used in Your Area  ______PVC       _______Poly
    - If using city or municipal water system, provide the following info below:
         Water Pressure _________ psi
         Type of service line  _____PVC/Poly     ______Copper    _____Galvanized
         Size of service line  _____3/4"     ______1"    _____1-1/4"
         Water Meter Size   _____5/8"     ______3/4"    _____1"

    - If using a pump system, provide the following info below:
         Type of the Pump delivery line
    ____PVC/Poly     ______Copper    _____Galvanized
         Size of the Pump delivery line  _____3/4"     ______1"    _____1-1/4"
         Capacity of your Well   _____ gpm
         Capacity of your Pump at the following pressures
    @30psi_____GPM   @40psi_____GPM   @50psi_____GPM

Getting Started

You'll need a pressure gauge, string and a pencil or pen, a 5 gallon bucket and a tape measure.

lawn watering

Check your water pressure:
Screw the pressure gauge onto the nearest faucet to the water meter. Make sure no water is running anywhere inside or outside your house. Turn on the faucet with the gauge attached. The gauge shows your water pressure in pounds per square inch (PSI). You may also call your local water company to find out your water pressure.

Write the pressure reading on your information sheet.

sprinkler system design service

Check your water meter size:
The meter size ( 5/8",3/4" or 1") is usually stamped on the outside of the meter. If you can’t find the size, just call the water company, they’ll know.

Write the meter size on your information sheet.

lawn watering system

Check the size of your service line:
Find the pipe that runs from the water meter to your house. Wrap a piece of string around the pipe, mark it, then measure how much string it took to go around the pipe. Check your string length on the table below to find your service line size. For example, if your string measures 4" and you have galvanized pipe, your service line is 1 inch.

Determining Size of Service Line:

Length of String 2 3/4" 3 1/4" 3 1/2" 4" 4 3/8" 5"
Size of Copper 3/4"   1"   1 1/4"  
Size of Galvanized   3/4"   1"   1 1/4"
Size of Sch. 40 PVC   3/4"   1"   1 1/4"

Write the service line size on your information sheet.

sprinkler design service

Measure your home’s water capacity (flow):

Get a measurable container, like a 5 gallon bucket, make sure no other water is running in or outside the house, turn the faucet on all the way and time how long it takes to fill the container.

Our 5 gallon bucket took 17.5 seconds to fill so; number of gallons divided by number of seconds to fill x 60 seconds = GPM (5 divided by 17.5 x 60 = 17.14). Round your answer down to the nearest whole number. Our example gives us 17 GPM.

Note: For pump systems, check with your well and pump dealer or the owner’s manual of your pump to determine its pressure and flow capacity.

Write your water capacity on your information sheet.

Measure your lot:
Include lawn, sidewalks, driveways, and walkways and don’t forget the house. It’s a good idea to sketch everything on a piece of scratch paper, and write in the measurements before drawing your final plan on the graph paper supplied. Then, just transfer everything, to scale, to the graph paper.

Mark your meter or pump location with a box , your desired timer with a circle ,and desired manifold locations with an .

On your graph paper, each 1-inch square can be 10, 20, or 30 feet. Decide your scale and write it on your information sheet (important). 

Dividing your lot into sections:

Divide your layout into sections, pick out the different areas like, the front lawn, side lawn, flowerbeds etc.

Be sure to label all areas of your yard that you want watered. We will make sprinkler head recommendations. If you have special watering requirements, such as wanting bubblers, label these areas. Also, if you have a particular area you want watered separately, such as gardens, roses, etc., mark that area ‘separate valves.’

Group similar types of plants together, like shrubs and ground cover. If you have big differences in the amount of sun different areas get, you may want to group them, too.


Upon completion, mail or fax the completed questionnaire and drawing along with payment ($150) to Dave McCullough. PLEASE ALLOW 2 WEEKS TO PROCESS YOUR DESIGN.

Mail or fax the completed questionnaire and your drawing and payment ($150)  to:

McCullough Sprinkler Design Service
401 Chester
Friendswood, Texas 77546
Fax: 281-482-4182

We offer this design service as a guideline. No guarantee of accuracy of design, system installation, or operation of system is implied.

IMPORTANT: The computerized plan you receive will only be as accurate as your drawing. Be sure to scale your drawing using one of the following ratios: 1"=10’ or 1"=20’ or 1"=30’.

Copyright © 2007 IRRIGATION CLASS. All Rights Reserved