SR0081813 - Laserfiche WebLink

Home Browse Search

5.5.1.5. Contamination can be avoided by doing one of the following • ballast the tank with a liquid compatible with the product being stored OR • clean the tank after ballasting to eliminate any contaminating product A WARNING Inert the tank and use inert gases (not air) to pressure test a tank that contains or has contained flammable or combustible liquids or vapors. Failure to follow this warning could result in an explosion, and could result in death or serious injury. A WARNING If flammable or combustible product is used as ballast, exercise special care in handling. Safeguard against sparks, fire or product spills. Failure to follow this warning could result in a fire or an explosion, and could result in death or serious injury. 6: POSTINSTALLATION TESTING 6.1. PRESSURE TESTING TANKS 6.1.1. If the tank is a water/wastewater tank equipped for pressure testing, follow the procedures in the Preinstallation Testing Instructions for Water/Wastewater Tanks Factory -Equipped for Pressure Testing supplement. See the Introduction for information on how to obtain this supplement. 6.1.2. All UL -label, ULC -label and potable watertanks must be pressure tested after backfill is brought close to the top of the tank. 6.1.3. If the tank is ballasted with water, the tank can be pressurized for pressure testing. See Pressure -Testing Sidebar. 6.2. OPTIONAL HYDROSTATIC TESTING 6.2.1. This optional test is typically used for water or wastewater tanks that are not pressure -testable due to the accessories on the tank. 6.2.2. Use the following procedure for this test: • Seal off the influent and effluent piping, and any fittings that are below the tank top with watertight caps or plugs. • Fill the tank with water to a level that is 3 inches [7.6 cm] into the access openings after the backfill is at least 75 percent of the way up the tank. • Let the water stand in the tank for a minimum of 1 hour (or longer if required by applicable local codes). • Allow sufficient time so that the water temperature stabilizes. • If the water level drops, check to see that plugs or caps sealing off the piping are tight.Then add more water to fill air voids and return the water level back to the standard testing level. • If the water level does not stabilize, contact the manufacturing facility that shipped the tank. 7: PIPING, VENTING AND CONTAINMENT SUMPS 7.1. INTERNAL PIPING 7.1.1. All piping must conform to all applicable codes and standards NOTICE All internal piping must be at least 4 inches [10 cm] from the tank bottom. Failure to follow this notice could result in damage to the tank and/or surrounding property. NOTICE All metal fittings and other metal components must be coated to protect against corrosion. Failure to do this could result in damage to these parts, the tank and/or surrounding property. 7.1.2. Fortanks equipped with manways, see table and relevant figure in Piping Sidebar to determine the correct length for internal piping. 7.1.3. For tanks equipped with access openings, see table and relevant figure in Piping Sidebar to determine the correct length for internal piping. 7.2. EXTERNAL PIPING A WARNING The tank must be isolated from all piping when the external piping is being pressure tested. The test pressures for external piping could cause tank failure, and could result in death or serious injury. 7.2.1. When extending monitoring or vapor -recovery piping to the surface, make sure the at -grade fittings are different from any fill fittings and will not accept standard fill hoses. NOTICE All connections to the tank must be flexible. Provisions must be made to accommodate movement and misalignment between the piping and the tank. Failure to do this could result in damage to the tank and/or surrounding property. 7.3. VENTING TANKS A WARNING All underground tanks/compartments shall be adequately vented to prevent the development of vacuum or pressure when filling or emptying the tank. Failure to properly vent a tank or compartment could cause tank failure, and could result in death or serious injury. 7.3.1. The primary tank is designed to operate at atmospheric pressure. 7.3.2. The tank's venting system must be adequately sized to ensure that atmospheric pressure is maintained at all times, including during filling and emptying of tank. 7.3.3. Whenever installing overfill protection, such as an alarm, an automatic shut-off device (fill pipe flapper valve) or a vent -restriction device (ball -float valve), follow the instructions provided by the manu- facturer of the overfill -protection device and consult the authority having jurisdiction to determine the level at which the overfill protection should operate. • Some jurisdictions do not allow ball -float valves. • Consult applicable codes and regulations. A WARNING Vent -restriction devices for overfill should not be installed if owner/operator will allow pump- or pressure -filling of tank. Failure to follow this warning could cause tank failure, and could result in death or serious injury. 23