Balance Type

A trial and error estimate is made for determining the diameter of the flare header based upon the maximum relieving flare load and considering the back pressure limitation of 10 percent for conventional valves and 40 percent for balanced type valves. Note, however, a single main header in most cases turns out to be too large to be economically feasible. Line sizing procedures are discussed in detail in the next subsection. 

The back pressure developed at the downstream section of any pressure-relief valve connected to the same headers should not exceed the allowable limit, i.e., 10 percent of the set pressure in psig for the conventional type and 40 to 50 percent of the set pressure in psia for the balanced type valve. 

The polymerization reactor is of the heat-balance type because of the change in the heat transfer characteristics of the reaction mass during the polymerization. As the viscosity increases, the rate of heat dissipation by mixing will generally decline, which must be taken into consideration in setting up the equipment and in taking the appropriate measurements. 

So in TSCA, we have a "balancing-type law" wherein the Administrator is required to consider not just the risks associated with a chemical, but also whether it is an unreasonable risk in light of the benefits associated with the chemical. For the Administrator to regulate a chemical substance or mixture under Section 6 of TSCA, the law requires that "the Administrator shall consider... 

This should not be too surprising. They started from scratch in 1977 with only a handful of people. Today the Office of Toxic Substances is 600 strong. In fairness to the Agency, it takes time to hire and train the people to do an effective job with a new "balancing-type" law. 

TSCA is a balancing-type law. It is concerned with unreasonable risks. It attempts to balance risks versus benefits for all chemicals and uses. The EPA administrator must consider (1) effects on health, (2) effects on the environment, (3) benefits and availability of substitutes, and (4) economic consequences. 

Pressure is measured extensively in the chemical processing industries and a wide variety of pressure measuring methods has been developed. Some of these have already been discussed in Volume 1, Section 6.2.2, viz. the manometer (which is an example of a gravity-balance type of meter), the Bourdon gauge (an example of an elastic transducer) and mention is made of the common first element in most pressure signal transmission systems—the differential pressure (DP) cell (Volume 1, Section 6.2.3). The latter also frequently forms part of a pneumatic transmission system and further discussion of this can be found in Section 6.3.4. 

No distillation calculations of any kind were carried out, other than the simple material balance type. It was assumed that all of the ammonium bicarbonate fed to a still would go to the distillate product, plus sufficient water to form a 13% ammonium bicarbonate solution, and that all of the sodium chloride plus the remaining water would be the still bottoms product. 

The Langmulr-B1odgett thln-fllm trough employed In this work was a Lauda Film Balance Type 1974 (Sybron-Brlnkmann, Toronto, Canada). 

In addition, a vasodilator in combination with an angiotensin-converting enzyme inhibitor has been used in congestive heart failure. The vasodilators may be classified as venodilators, arterial dilators, or balanced-type vasodilators. 

Figure 3.9 Stratification-circulation diagrams used to describe a spectrum of circulation and geomorphometric types of estuaries that can be defined by stratification. Estuarine types are as follows Type 1 estuaries are those without upstream flow requiring tidal transport for salt balance Type 2 estuaries are partially mixed (e.g., Marrows of the Mersey (NM) (UK), James River (J) (USA), Columbia River estuary (C) (USA) Type 3 estuaries are representative of fjords [e.g., Siver Bay (S), Strait of Juan de Fuca (JF) (USA)] and Type 4 estuaries indicative of salt wedge estuaries [e.g., Mississippi River (M) (USA)]. The basic classification parameters are as follows the stratification is defined by SS/Sq where SS is the difference in the salinity between surface and bottom water and So is the mean-depth salinity, both averaged over a tidal cycle and Us/Uf, where U is the surface velocity (averaged over a tidal cycle) and Uf is the vertically averaged net outflow. The subdivisions a and b represent values where SS/Sq <0.1 and SS/Sq >0.1, respectively subscripts h and 1 refer to high and low river flow. The curved line at the top represents the limit of surface freshwater outflow. (From Hansen and Rattray, 1966, as modified by Jay et al., 2000, with permission.)...

It has been possible to produce a balanced type of anesthesia wherein low-potency N20 is combined with an opioid analgesic, usually the meperidine analog fentanyl (Fig. 5-10), or the more recent analogs sufentanil and alfentanil. When a butyrophenone-type neuroleptic (see later), particularly droperidol, is added, a state of neuroleptoanesthesia is produced where, without loss of consciousness, analgesia sufficient for surgery is achieved during which the patient still responds to commands.6... 

Flosequinan is a vasodilator. Vasodilators in combination with an angiotensin-converting enzyme (ACE) inhibitor have been used in congestive heart failure. The vasodilators may be classified as venodilators, arterial dilators, or balanced-type vasodilators (Table 26). The rationale for vasodilation in the management of CHF is based on the increased arteriolar vasotone that occurs. This initiates a vicious circle in which cardiac function is further depressed by an increase in afterload and in resistance to ejection. 

The vasodilators may be classified as ventodilators, arterial dilators, or balanced-type vasodilators (Table 26). 

Energy balance type thermal mass meter. (Adapted from "Flow Measurement," http //en.wikipedia.org/wiki/Flow Measurement.)... 

These valves are classified as conventional or balanced depending on the effects of back pressure on their performance. The conventional type pop valve is used where pressure is released to the atmosphere or to a low-pressure relief header. The balanced-type pop valve is used where a relatively high pressure exists or is built up in the relief header. 

Mass balance-type studies represent an important laboratory experiment, in which the fate of the entirety of a parent compound is modeled in an environ-... 

Films made of atactic polystyrene (PS Asahi Dow, Japan), bisphcnol-A polycarbonate (PC Teijin Kawi, Japan) and nylon 6 (Ube Kosan, Japan) were used for plasma treatment. Both PS and PC films were prepared by melt-pressing and slow cooling, and nylon 6 film was prq>a(ied by mch-pressing and quenching. Balance-type commercial nyltn 6 film (Unitika, Japan) was also u. ... 

Figure 7 shows the temperature dependence of tan 8 of nylon 6 films the melt-pressed and quenched, the melt-pressed and slowly-cooled, and the balance-type (two axis expanded) commercial films. The packaging of molecule becomes tight in that order. The tan 5 curves of these specimens show different behaviors, but these curves include at least two relaxation peaks. One is near 40°C, and the other near 90"C the former corresponds to the Tg, and the latter corresponds to the relaxation of the crystalline region. ... 

Balance type commercial film (two-directional stretdiing film)... 

The manufacture of cellulose blown films from NNMO solution [48] was mentioned in Section 3.5.2 and mechanical values of a more anisotropic film as well as a more balanced type are included in Table 3.4 demonstrating the versatility of the process. 

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