Piping System Components

Chatrathi et al. (2001) recently reported some experiments on flame propagation in indnstrial scale piping. They presented data on deflagration propagation in three sizes of pipes (6-inches, 10-inches, and 16-inches) and three fnels (propane, ethylene, and hydrogen). The effects of bends were evalnated, bnt other piping system components were not evaln-ated. The conclnsions from this work are as follows ... 

Equation 2-25 is valid for calculating the head loss due to valves and fittings for all conditions of flows laminar, transition, and turbulent [3], The K values are a related function of the pipe system component internal diameter and the velocity of flow for v-/2g. The values in the standard tables are developed using standard ANSI pipe, valves, and fittings dimensions for each schedule or class [3]. The K value is for the size/type of pipe, fitting, or valve and not for the fluid, regardless of whether it is liquid or gas/vapor. 

This section covers piping system components other than assemblies consisting of pipe and fittings joined by circumferential welds. 

Liquid penetrant examination shall be performed on all welds connecting to hydrogen piping system components which are not radiographed. 

ISO 11468 1997 Plastics - Preparation of PVC pastes for test purposes - Dissolver method ISO 12092 2000 Fittings, valves and other piping system components made of unplasticized poly(vinyl chloride) (PVC-U), chlorinated poly(vinyl chloride) (PVC-C), acrylonitrile-butadiene-styrene (ABS) and acrylonitrile-styrene-acrylester (ASA) for pipes underpressure - Resistance to internal pressure - Test method... 

Dry pipe system components containing water should be protected from freezing. 

A series of typical vacuum insulated piping system components may comprise valves, straight sections, elbows and tees in sizes 1 in., 2 in., 4 in. and 6 in. OD. The working pressure is 200 psi. Vacuum jackets are evacuated and sealed as a step in the fabrication procedure. The manufacturing techniques needed are similar to those which have been previously proven by performance in other cryogenic equipment. 

PFD s are the schematic illustrations of the piping system description. PFD s show the relationship between the major piping system components. PFD s do not show pipe ratings or designations, minor piping systems, for example, sample lines or valve bypass lines instrumentation or other minor equipment, isolation valves, vents, drains, etc. Figure 4.2 lists the typical items found on a PFD. 

Construction materials are compatible with piping, system components and system temperature. 

AN EXAMINATION OF THE RELATIVE IMPACT OF COMMON POTABLE WATER DISINFECTANTS (CHLORINE, CHLORAMINES AND CHLORINE DIOXIDE) ON PLASTIC PIPING SYSTEM COMPONENTS... 

The three most eommon disinfectants in potable water are ehlorine, chloramines and chlorine dioxide. While these disinfectants are all oxidants, their uniqne eharacteristics can residt in a significantly different impact on the performance of plnmbing system components. In this paper, the chemistry and characteristics of the oxidants are discussed in the context of oxidative degradation of plastic piping system components. Testing strategies to ensure material performance in potable water applications are presented and reviewed. 

AN EXAMINATION OF FIELD FAILURES OF PLASTIC PIPING SYSTEM COMPONENTS IN POTABLE WATER APPLICATIONS... 

Disinfectants in potable water, such as chlorine and chlorine dioxide, can impact the performance of plastic piping system components. In this paper, field failures of plastic piping components exposed to potable water are examined. Analysis of the oxidative and mechanical initiation and propagation mechanisms leading to failure is performed. Field and laboratory samples are also compared to assess the test methodologies that are available to evaluate the impact of disinfectants on plastic piping systems. 

S. Chung, K. Oliphant, P. Vibien and J. Zhang, An Examination of the Relative Impact of Common Potable Water Disinfectants (Chlorine, Chloramines and Chlorine Dioxide) on Plastic Piping System Components, PPXIII, Washington D.C. (2006). 

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