INSTALLATION AND SERVICE RECOMMENDATIONS
FOR “SMALL TUBE”
SHELL AND TUBE HEAT EXCHANGERS
Installation (Typical Oil Cooler)
The satisfactory use of heat exchange equipment is dependent upon certain precautions, which must be taken at the time of the installation.
(1) Connect and circulate the hot fluid in the shell side (over small tubes) and the cooling water in the tube side (inside small tubes).
(2) If an automatic water-regulating valve is used, place it on the inlet end of the cooler. Arrange the water outlet piping so that the exchanger remains flooded with water, but at little or no pressure. The temperature probe is placed in the hydraulic reservoir to sense a system temperature rise.
(3) There are normally no restrictions as to how this cooler may be mounted. The only limitation regarding the mounting of this equipment is the possibility of having to drain either the water or the oil chambers after the cooler has been installed. Both fluid drain plugs should be located on the bottom of the cooler to accomplish the draining of the fluids. Drains are normally available on all models.
(4) It is possible to protect your cooler from high flow and pressure surges of hot fluid by installing a fast-acting relief valve in the inlet line to the cooler.
(5) It is recommended that water strainers be installed ahead of this cooler when the source of cooling water is from other than a municipal water supply. Dirt and debris can plug the water passages very quickly, rendering the cooler ineffective.
(6) Fixed bundle heat exchangers are generally not recommended for steam service. For steam applications, a floating bundle exchanger is required.
(7) Piping must be properly supported to prevent excess strain on the heat exchanger ports. If excessive vibration is present, the use of shock absorbing mounts and flexible connectors is recommended.
Each heat exchanger has been cleaned at the factory and should not require further treatment. It may be well to inspect the unit to be sure that dirt or foreign matter has not entered the unit during shipment. The heat exchanger should be mounted firmly in place with pipe connections tight. CAUTION: If sealant tape is used on pipe threads, the degree of resistance between mating parts is less, and there is a greater chance for cracking the heat exchanger castings. Do not over-tighten. When storing the unit, be sure to keep the oil and water ports sealed. If storage continues into the cold winter months, the water chamber must be drained to prevent damage by freezing.
Performance information should be noted and recorded on newly installed units so that any reduction in effectiveness can be detected. Any loss in efficiency can normally be traced to an accumulation of oil sludge or water scale.
Replace gaskets when removing end castings.
Use salt water in special models having 90/10 copper—nickel tubes, tube sheets, bronze bonnets and zinc anodes on the tube side. Brackish water or other corrosive fluids may require special materials of construction.
When zinc anodes are used for a particular application, they should be inspected two weeks after initial startup. At this time, by visual inspection of the anode, determination of future inspection intervals can be made, based on the actual corrosion rate of the zinc metal. The zinc anodes must be replaced when 70% of the zinc volume has been consumed.
It may be necessary to drain the water chambers of the exchanger to protect it from damage by freezing temperatures. Drains are provided in most standard models.
The oil chamber of the exchanger may become filled with sludge accumulation and require cleaning. It is recommended that the unit be flooded with a commercial solvent and left to soak for one—half hour. Back flowing with the solvent or regular oil will remove most of the sludge. Repeated soaking and back flowing may be required, depending on the degree of sludge buildup.
It may be necessary to clean the inside of the cooling tubes to remove any contamination and/or scale buildup. For severe problems, the use of a brush through the tubes may be of some help. Be sure to use a soft bristled brush to prevent scouring the tube surface causing accelerated corrosion. Upon completion of cleaning, be certain that all chemicals are removed from the shellside and the tubeside before the heat exchanger is placed into service.
Courtesy TTP 1092