AWWA C909-16 pdf download.Molecularly Oriented Polyvinyl Chloride (PVCO) Pressure Pipe, 4 In. (100 mm) and Larger
The following defnitions shall apply in this standard:
1. Constructor: Te party that provides the work and materials for place- ment or installation.
2. Design factor (DF): Te inverse of the safety factor. It is used to reduce the hydrostatic design basis (HDB) to arrive at the hydrostatic design stress (HDS) from which the pressure class (PC) is calculated. Unless otherwise noted, the design factor used in this standard is 0.5. Note: Because the efective strength of PVCO materials depends on the tem- perature and on the duration of stress application, the efective safety factor when using a DF of 0.5 will vary with end-use conditions. For the PVC material described in this standard, the efective safety factor against sustained pressures is at least 2.0. Te actual value is generally larger and depends on the magnitude of the applied transient and sustained pressures as well as on the operating temperature.
3. Expansion ratio (ER): Te ratio of the outside diameter of the fnished PVCO pipe to the outside diameter of the original starting stock.
4. Hydraulic transients: Hydraulic transients (sometimes called water hammer) are pressure fuctuations caused by changes in the velocity of the water column resulting from such actions as operating a valve or a pump. Te pressure fuctuations can be positive or negative (see Surge pressure). Hydraulic transients caused by normal pump and valve operation require the pipe system to withstand the resultant positive and negative pressures unless surge protection is provided.
5. Hydrostatic design basis (HDB): Te categorized long-term strength in the circumferential or hoop direction as established from long-term pressure tests in accordance with ASTM D2837. Tis standard requires the use of PVC com- pounds that qualify for an HDB rating of 4,000 psi (27.58 MPa) and fnished pipe that qualifes for an HDB rating of 7,100 psi (49.0 MPa).
6. Hydrostatic design stress (HDS): Te maximum allowable working hoop stress in the pipe wall when the pipe is subjected to sustained long-term hydrostatic pressure. Te HDS in this standard is established by multiplying the HDB by the DF of 0.5.
7. Inspector: Te authorized representative of the purchaser who is entrusted with the inspection of products and production records. Te inspector also observes the production operations and quality-control tests to ensure products comply with the requirements of this standard and the purchaser.AWWA C909-16 pdf download.