General Code Requirements

It is essential that the ASME code requirements be understood by the designer and individual rating and specifying the installation details of the safety device. It is not sufficient to merely establish an orifice diameter, since process considerations which might cause overpressure must be thoroughly explored in order to establish the maximum relieving conditions. 

An abbreviated listing of the key rating provisions is given in paragraphs UG-125 through 135 of the ASME code, Section 8, Div. 1, for unfired pressure vessels [1]. 

All pressure vessels covered by Division 1 or 2 of Section VIII are to be provided with protective over- 

Applied Process Design for Chemical and Petrochemical Plants 

Rupture disks may be used to satisfy the requirements of the code for conditions such as corrosion and polymer formations, which might make the safe-ty/relief valve inoperative, or where small leakage by a safety valve cannot be tolerated. They are particularly helpful for internal explosion pressure release. 

---

Conventional valves, 400, 402, 407, 438 External fires, 450, 453 General Code requirements, 412, 415. 420-425... 

Cross-country gas pipelines generally must odorize the normally odorless, colorless, and tasteless gas ia urban and suburban areas, as is required of gas distribution companies. Organosulfur compounds, such as mercaptans, are usually used for this purpose, and code requires that the odor must be strong enough for someone with a normal sense of smell to detect a gas leak iato air at one-fifth the lower explosive limit of gas—air mixtures. The latter is about 5%, so the odorant concentration should be about 1%, but most companies odorize more heavily than this as a safety precaution. 

Impact Testing Materials conforming to ASTM specifications listed in the code may generally be used at temperatures down to the lowest temperature listed for that material in the stress table without additional testing. When welding or other operations are performed on these materi s, additional low-temperature toughness tests may be reqiiired. The code requirements are listed in Table 10-57. 

The national codes and standards dictate the minimum requirements, and give general guidance for design and construction any extension beyond the minimum code requirement will be determined by agreement between the manufacturer and customer. 

Joining Nonmetallic Pipe All joints should be made in accordance with procedures complying with the manufacturer s recommendations and code requirements. General welding and heat fusion procedures are described in ASTM D-2657. ASTM D2855 describes general solvent-cementing procedures. 

This subsection provides a general synopsis of code requirements. It should not be viewed as comprehensive. 

Based solely on the national code requirements, a generalized work area for CNG vehicles can be developed, as shown in Figure 5-2. 

Fig. 5-2 General Electrical Requirements for CNG Repair Areas Based on Modification of National Codes. (Source Ref. 15.7])...

As already mentioned, this is just a typical general specification which could be sent to a manufacturer, and it will typically determine the general design and code requirements to which the SRVs must comply. This general specification is accompanied by a complete detailed technical data sheet per SRV, of which a typical example for the spring and pilot valve can be found in API 526 (see examples in Appendix K). 

With the European Patent Convention in mind, these patent applications appear hopeless. But rather pragmatic or missing definitions provided by the US Code do not exclude discoveries from being patented. The USC states that "patentability shall not be negotiated by the manner in which the invention was made" (35 USC, 103). Based on this definition of inventiveness and generally low requirements to prove utility, it appears less hopeless to get the above-mentioned patent application granted. This is especially true if... 

Computational Errors. Errors in computation can be attributed to two specific circumstances convergence criteria and improper selection of parametric equations. Most geochemical codes require that mass balance and mass action equations be solved to obtain an acceptable mathematical model of the aqueous solution. Minimal error can be attributed to the mathematical formulation of the equation solvers, because such narrow convergence criteria are used in the matrix inversion or iterative solution algorithms. Numerical dispersion or out of bounds computations generally do not occur unless phase boundaries are exceeded. 

There are two main situations concerning deflection of boards that may not pass the building code requirements deck boards at a certain span (distance between neighboring joists) and stair tread at a certain span. Let us consider these situations using the same examples Trex composite deck boards and GeoDeck composite deck boards. These examples would illustrate general shortcomings of plastic-based composite deck boards in terms of their flexibility and deflection. 

In the same 25-ft tunnel test the so-called smoke development index (SDI) can also be determined. The smoke measurement is based on the percentage of retardation of light passing through the tunnel exhaust stream and detected by a photocell, and then data obtained are converted to the SDI, with red oak flooring set at 100. AC 174 does not specify any particular SDI as the code requirement, but the industry generally considers SDI above 450 as hazardous and not acceptable, particularly for interior flnish. 

---