Water lines, installing

Structures or pits for water lines are mostly of steel-reinforced concrete. At the wall entrance, contact can easily arise between the pipeline and the reinforcement. In the immediate vicinity of the pit, insufficient lowering of the potential occurs despite the cathodic protection of the pipeline. Figure 12-7 shows that voltage cones caused by equalizing currents are present up to a few meters from the shaft. With protection current densities of 5 mA mr for the concrete surfaces, even for a small pit of 150 m surface area, 0.75 A is necessary. A larger distribution pit of 500 m requires 2.5 A. Such large protection currents can only be obtained with additional impressed current anodes which are installed in the immediate vicinity of the pipe entry into the concrete. The local cathodic protection is a necessary completion of the conventional protection of the pipeline, which would otherwise be lacking in the pit. 

Sprinkler and water spray installations-Many process and storage area buildings should be protected by automatic sprinkler systems. The size and arrangement for water supply are dependent upon the nature of the hazard and the degree of protection desired. Water spray installations are particularly adapted for cooling uninsulated steel structures, elevated pipe lines, vessels, spheres, and similar plant installations. 

The rationale for these simple approaches to water treatment is the argument that these kinds of systems have minimal requirements for MU water and are therefore subject to a reduced level of risk. In practice, the validity of this argument is suspect but is difficult to prove because totalizing water meters are seldom installed on the MU water line. 

Running gas lines into a laboratory is not difficult once it has been determined where they are needed. It may simplify plumbing installation to have rough plumbing for gas terminate close to the water lines. When estimating total requirements for gas, it should be kept in mind that it may also be needed for a water heater and a heating unit for the building. 

Anyone who has remodeled a house is very aware of this. Consider the example of a man who builds a house and doesn t have the capital to include a second bath. He realizes, however, that when his children become teen-agers he will definitely need another one. Therefore, if he is wise he will design the house so that there is space for another bath. He will also make sure that the hot and cold water lines, a drain, and a stack that can service the second bath are installed. These provisions for the future will only increase the cost of the house slightly. Then five years later when he installs the second bath he merely needs to buy the fixtures and attach them to the installed plumbing. 

Cooling water inlet and outlet temperatures are 80 and lOS F, respectively. The condenser heat transfer area is 1000 ft. The cooling water pressure drop through the condenser at design rate is 5 psi. A linear-trim control valve is installed in the cooling water line. The pressure drop over the valve is 30 psi at design with the valve half open. 

Unattended operations must be planned with automatic safety switches that prevent serious damage (fire, flooding, explosion) in case of accidental equipment failure or interruption of utility services such as electricity, water, or gas supplies. Of special concern are the constant flow of cooling water and the operation of high-temperature baths. In the case of water flow, a device should be installed in the water line to (1) automatically regulate the water pressure (so as to avoid surges that might disconnect or rupture a water hose), and (2) automatically turn off electrical connections and water-supply valves in case of a total loss of water supply. In the case of hot thermostat baths or ovens, a sensor/control device should be installed that automatically turns off the electrical power to all heaters if the temperature exceeds some preset upper limit. 

Other applications for water meters, besides the water line where the fluoride is injected as discussed above, are on supply lines for solution makeup water. Additionally, a flow meter is a necessity when a sodium fluoride saturator is used to prepare the fluoride solution, (see Section 5.) Because the water usage rate in a saturator installation is minimal, the meter must be the smallest available (usually 1/2 in 1 in. = 2.54 cm). A propeller type is commonly used here. 

Connect the cold-water supply line to the water intake connection of the saturator. Upstream of this connection, the water line should have a small water meter (1/2 in.) for use in calculating the feed rate, and there should be a shut-off valve between the meter and the saturator. To lower the amount of dirt to the saturator, a sediment filter (20 mesh) should be installed upstream of the saturator between the softener and water flow meter. 

Dow Benelux, a petrochemical industry situated along the Scheldt estuary (Temeuzen, NL) used this intermittent chlorination technique. If bivalve molluscs at the exit of the cooling water lines could sense sufficient free chlorine to cause them close their shells, then this would imply that all organisms present in the line before this point would experience even higher concentrations, and therefore would be unable to attach themselves to the walls. Thus a Musselmonitor was installed to tune the minimum amount of chlorination to be effective. This proved to be very beneficial, both environmentally and financially (reduction of hypochlorite and pumping energy, less off time for maintenance) (Paping, 1991). 

The primary disadvantages of cryogenic probes are that they are very expensive, require more physical infrastructure like chilled water lines than a conventional probe, and are difficult to install and remove. Most facilities with cryogenic probes keep them in dedicated instruments and only remove them for maintenance or repair. This works well for groups with similar samples and needs. Cryogenic probes typically have fixed frequencies and cannot replace the flexibility of broadband probes for unusual nuclei. 

Pipe Lines Installation of water pipes and gas pipes is another important aspect for furnishing a science laboratory. While installing pipes some of the points that be given due consideration are given as follows ... 

Installing direct current (DC) electrical-based remediation systems in urban areas also requires containment of stray voltage and current. DC systems can cause corrosion of buried gas and water lines or wreak havoc on cathodic protection systems. A good design can minimize the impacts, but sometimes, extra sacrificial anodes need to be installed to contain the electric field, adding to the cost of installation. 

Plumbing rough- Work performed by the plumbing contractor after the Rough Heat is installed. This work includes installing all plastic ABS drain and waste lines, copper water lines, bath tubs, shower pans, and gas piping to furnaces and fireplaces. Lead solder should not be used on copper piping. 

A major problem with most eyewash stations and deluge showers is that they are usually connected to the cold water line. The ANSI standard requires that the water be tepid but does not define what tepid is. Typically, tap water temperatures are in the 60"F to 70"F (15.5" to 21 C) temperature range, but in colder climates can be much less during the winter. Water at temperatures in the 50 s or lower can be painful itself, and in extreme cases can cause the injured person to go into shock. Although relatively few eyewash installations are capable of conveniently providing it, lukewarm water with temperatures close to body temperatures between 90" and 95"F (32 to 35"C) would be ideal. 

Electric DisposaL A disposer can be installed in any sink that has a full-size drain opening. For an assistive kitchen design, switch location, safety, and disposal location are the main design objectives. The on and off switch should be placed in an accessible area, possibly under the front lip of the countertop. Care should be taken not to position the switch where a wheelchair can accidentally bump the switch while the person is washing the dishes. It should also be located so that a person cannot contact the sink and switch at the same time. The electrical connection should be away from the water line and should be protected with a conduit pipe to eliminate any shock hazard. The disposal should be located away from any wheelchair-accessible area. 

The treated brine handled in the clarifier is alkaline and not highly corrosive. At least in diaphragm plants, carbon steel often can be used as the major material of constmction. Since brine is more corrosive in the presence of oxygen, those parts near or above the water line are sometimes coated. With mercury or membrane cells, there is also the possibility of pickup of harmful elements to be considiered. It is common practice to use coated walls and rubber-covered internals in these cases. When clarifiers are installed at grade level, the bottoms are frequently of concrete. This too is more characteristic of diaphragm-cell plants. Membrane cells can be damaged by pickup of such compounds as sulfates and silica. 

Before excavation work begins, OSHA rules require contractors doing the work to determine the estimated location of utility installations — sewer, telephone, fuel, electric, water lines, or any other underground installations — that may be encountered during digging. 

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