Water tanks

The acceptance test for the water storage tank should follow the requirements of the design specification. 

Sprinkler system acceptance test requirements are detailed in NFPA 13. This section highlights some of the important factors in acceptance test of sprinkler systems. 

The completed installation should be checked against the approved working drawings to verify that the installation is in accordance with the design specifi- 

Design coverage is the square foot coverage per sprinkler and is the product of the distance between branch lines times the distance between sprinklers on branch lines. Also, the distances from end branch lines and end sprinklers on branch lines to wall must be checked to verify these distances do not exceed one-half the distance between branch lines or sprinklers on branch lines. This has a direct bearing on the coverage at the perimeter of the building. 

To ensure proper drainage, inspection personnel must examine overhead piping for proper pitch. Sprinkler systems are designed to drain back to the sprinkler riser, where a 2 in (5.1 cm) valve drain outlet is provided. When this is not possible and some piping is trapped, supplementary low point drain valves should be provided. Low-point drains should be shown on the system drawings. 

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As any conventional probe, acoustic beam pattern of ultrasound array probes can be characterized either in water tank with reflector tip, hydrophone receiver, or using steel blocks with side-drilled holes or spherical holes, etc. Nevertheless, in case of longitudinal waves probes, we prefer acoustic beam evaluation in water tank because of the great versatility of equipment. Also, the use of an hydrophone receiver, when it is possible, yields a great sensitivity and a large signal to noise ratio. 

A series of tests were performed at the AFC s National Reactor Testing Station in Idaho, starting in 1953. The reactor was situated outdoors, and was operated remotely. The core of the first version had fuel assembhes of aluminum and enriched uranium plates of the Materials Testing Reactor (MTR) type, installed in a water tank. One of the five control rods could be ejected downward and out of the core by spring action upon intermption of a magnet... 

Many redundant safety features were provided at the SRP. These included a moderator dump tank, gadolinium nitrate solution as emergency absorber, continuously mnning diesel generators, and a 95 x 10 -L (25 x 10 -gal) elevated water tank for each reactor, for assurance of cooling. 

Coatings for potable water tanks must not impart taste or odor to the water and must not allow corrosion products to enter the water. Epoxy coatings ate usually used. In the United States these coatings must be approved by the National Sanitation Eoundation, acting as agent for the U.S. Environmental Protection Administration. Complete cute is very important and up to two weeks at 20°C may be necessary. 

Environment Pump housing submerged in a cooling water tank, pH 5-8, 55-90°F (13-32X)... 

Slides Springs of various types multi-leaf springs on trucks, automobiles, steam locomotives, etc. light pressure vessels - e.g. aeroplane fuselages cheap pressure vessels - e.g. water tanks, nuclear reactor vessels metal rolling stand. 

Cement coatings are usually applied as linings for water pipes and water tanks, but occasionally also for external protection of pipelines [7]. Cement is not impervious to water, so electrochemical reactions can take place on the surface of the object to be protected. Because of the similar processes occurring at the interface of cement and object and reinforcing steel and concrete, data on the system iron/ cement mortar are dealt with in this chapter taking into account the action of electrolytes with and without electrochemical polarization. To ensure corrosion protection, certain requirements must be met (see Section 5.3 and Chapter 19). 

Internal Cathodic Protection of Water Tanks and Boilers... 

Internal cathodic protection of water tanks and boilers is most economical if it is taken care of at the design stage. It can, however, be installed at a later stage as a rehabilitation measure to halt the progress of corrosion. Tanks and boilers in ships were described in Section 17.4. Further applications of internal protection are dealt with in Chapter 21. 

Fig. 20-4 Safety precautions for water tanks (a) and filter tanks (b) to prevent danger of explosion from hydrogen.

The electrolysis protection process using impressed current aluminum anodes allows uncoated and hot-dipped galvanized ferrous materials in domestic installations to be protected from corrosion. If impressed current aluminum anodes are installed in water tanks, the pipework is protected by the formation of a film without affecting the potability of the water. With domestic galvanized steel pipes, a marked retardation of the cathodic partial reaction occurs [15]. Electrolytic treatment alters the electrolytic characteristics of the water, as well as internal cathodic protection of the tank and its inserts (e.g., heating elements). The pipe protection relies on colloidal chemical processes and is applied only to new installations and not to old ones already attacked by corrosion. 

Fig. 20-13 Current and potential-time curves for a 500-liter stainless steel water tank. Impressed current protection with an interrupter potentiostat X (20 C) = 2250 IJ.S cm-i c (CF) = 0.02 mol L" 60 C.

After several years of operation, protection current densities between 50 and 450 /lA m were measured on several vessels. The filter tanks and pure water tanks were provided with protection current by separate current circuits. This was necessary because the nozzle bottom out of the filter tank made it impossible to supply the pure water tank with sufficient protection current. 

Cathodic protection by means of impressed current is very adaptable and economic because of the long durability of anodes and the large number of anode materials and shapes. Some examples are described here. Internal cathodic protection of fuel oil tanks has already been dealt with in Section 11.7. The internal protection of water tanks is described in detail in Chapter 20. 

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