This presentation will cover Pipe Clamps, including Hold-Down Clamps, Riser Clamps, Clevis Hangers, Yoke U-Bolt Clamps, and Structural Supports. Learn how the appropriate type of pipe support is chosen based on the different design conditions. Find out how Finite Element Analysis is used in the design process and view the custom pipe supports designed for extreme applications.
January 23rd: Constant Spring Supports Design and Application Webinar 10:00 am OR 2:00 pm
January 30th: Pipe Support Field Inspection, Installation and Maintenance Webinar 10:00 am OR 2:00 pm
So, you have an existing water distribution system feeding a small hospital and a military post. Now you need to branch off the pipeline to feed another 30 new houses under construction nearby. How do you do it without interrupting service to the critical facilities already being served? In this Iron Strong Blog, we&#;ll discuss three common pipe tapping methods used in the water and wastewater industry and the variables to consider when choosing the best method for your waterworks project.
Tapping, also known as hot tapping or pressure tapping, allows a utility to tie into a pressurized system by drilling or cutting safely into an existing pipe. It involves placing a tapping fitting onto a water main, in addition to a gate or ball valve that will control water flow. At the same time, the water stream remains under pressure without interrupting or emptying the section of pipe. This means a pipeline can continue to operate while maintenance or modifications are being done to it.
The three methods of tapping are Direct Tap, Tapping Saddle, and Tapping Sleeve. These taps are typically installed to be used as "Service Taps" and may, in some cases, be installed in place of a Tee to provide an additional branch for a water system.
First, it can be performed on a new line before being placed in service. This method is known as a Dry Tap. Recommendation: Install Dry taps on new water lines after the completion of the required hydrostatic test.
How do I complete a successful Hydrostatic test? Click here for a helpful step-by-step blog with a video and a downloadable Tip Sheet.
The second method is known as a "Wet Tap." Wet tapping is the process of connecting a new service to an existing pipe installation without interrupting the service at any point. Services to homes, etc., connected to water lines that have been in service beyond their projected life typically remain in service until the new water line has been installed. New services are then installed and connected to the home. The homeowner, therefore, will see no interruption in service.
Only AWWA Only AWWA C900 pressure Class 150 and 200 PVC pipes 6 in. (150mm) through 12 in. (300mm) can be direct tapped.
For more information on tap size, check out this blog by Jeff Houser What is the Maximum Tap Size for Ductile Iron Pipe.
Link to Solid
Saddle tapping is the process of installing the service line to a main by a Corporation Stop. The corporation stop is screwed into a metal saddle that wraps around the pipe. When a pipe is saddle-tapped, equipment is attached to the corporation stop that permits a cutting tool to be fed through the stop to cut a hole in the pipe. During this process, the pipe wall is not threaded as the corporation stop is installed /&#;threaded&#; into the tapping saddle.
When using Saddles, an essential factor to consider is the pipe's Standard Dimension Ratio (SDR). HDPE pipe with an SDR number greater than 17 (SDR 19, 21, 26, 32.5) has a lesser wall thickness and can be subject to flexing.
Extra considerations should be made when selecting Service clamps or Saddles for PVC. Service saddles /clamps should not have;
These extra strapping considerations are not required for Ductile iron.
The maximum outlet size with a service clamp or saddle shall be 2 inches. If a tap larger than 2 inches is required, a tapping sleeve and valve shall be used. &#; AWWA M23 Manual
A tapping sleeve allows access to and the branching of an existing water main. Tapping sleeves can be used on Ductile iron pipe and alternate pipe materials. The benefits of using Tapping Sleeves are the size and stability of the sleeve. The branch may be well above the sizing for the Direct taps. The sleeve length makes this a good option when tapping PVC and HDPE, as the hoop strength of the sleeve may exceed that of the pipe. The downsides to using Tapping Sleeves are an additional cost for the sleeve and increased installation time which elevates costs.
Unlike DI pipe, direct threading of polyethylene pipe is not recommended. Sidewall fusion is the recommended method when installing service connections on polyethylene pipe. The fusion process requires specialty tools, an AC power source, and specific weather conditions. These factors can significantly affect the time and cost-efficiency of your project.
Another study performed by DIPRA, Direct Service Connection Installation Comparison DI pipe vs. Polyethylene Pipe, concluded that the average time to tap DI pipe was 15.67 minutes compared to an average of 69 minutes to tap into HDPE pipe.
We have looked at the three methods of tapping water lines. Direct tapping is the most common and cost-effective method of the three. Tapping Saddles and Sleeves increase the project's overall cost as both methods will increase the cost of materials, installation costs, and the use of dissimilar metals in the system. When it comes to service connections with Ductile iron, you save time and money. Most importantly, you have a secure connection when properly installed.
With the rate at which our communities and businesses continue to grow, along with their expectations for uninterrupted water service, the need to tap an existing water line will arise. Careful consideration of all three tapping methods will increase the potential for successful project completion and long-term system service.
If you have any questions regarding your water or wastewater infrastructure project, be sure to reach out to your local McWane Ductile representative. We have team members who've managed small and large water utility systems, served in engineering consulting firms, and bring decades of experience in solving field issues involving pipeline construction and operation. From design to submittal to installation, we strive to provide education and assistance to water professionals throughout the water and wastewater industry.
For more Ductile Iron Saddle Clampinformation, please contact us. We will provide professional answers.