BT-523 GST-250 PSI VERTICAL STORAGE TANKS 1500 Gallons Through 20,000 Gallons 9918-7523 2/23/2012 Do not attempt to use or maintain these units until you read and understand these instructions. Refer to the TaylorWharton’s Safety First booklet (TW-202) for handling cryogenic material. Do not permit untrained persons to use or maintain this equipment. If you do not understand these instructions, contact your supplier for additional information.
TABLE OF CONTENTS SAFETY PRECAUTIONS FOR LIQUID OXYGEN ......................................................................... 4 SAFETY PRECAUTIONS FOR LIQUID NITROGEN ..................................................................... 6 INTRODUCTION ................................................................................................................................. 7 FUNCTIONAL DESCRIPTION ..................................................................................................
Tanks in Oxygen Service ........................................................................................................ 21 Tanks In Nitrogen/Argon Service........................................................................................... 21 MAINTENANCE................................................................................................................................ 22 General ......................................................................................................
WARNING Following safety precautions are for your protection. Before performing installation, operating, or maintenance procedures read and follow all safety precautions in this section and in reference publications. Failure to observe all safety precautions can result in property damage, personal injury, or possible death.
Extreme Cold - Cover Eyes and Exposed Skin Accidental contact of liquid oxygen or cold issuing gas with the skin or eyes may cause a freezing injury similar to frostbite. Handle the liquid so that it won't splash or spill. Protect your eyes and cover the skin where the possibility of contact with the liquid, cold pipes and cold equipment, or the cold gas exists. Safety goggles or a face shield should be worn if liquid ejection or splashing may occur or cold gas may issue forcefully from equipment.
SAFETY PRECAUTIONS FOR LIQUID NITROGEN Nitrogen is an inert, colorless, odorless, and tasteless gas, which makes up four-fifths of the air you breathe. Liquid nitrogen is obtained by cooling air until it becomes a liquid and then removing the oxygen, which makes up the other fifth of the air. Liquid nitrogen is at a temperature of 320 degrees below zero Fahrenheit (-196°C) under normal atmospheric pressure.
INTRODUCTION This manual provides information for the user to operate and maintain Taylor-Wharton's GST-250 model cryogenic storage tanks which can be supplied with Taylor-Wharton Final Piping or customer specific Final Piping Options. These tanks are suitable for the storage and delivery of liquid oxygen, nitrogen or argon at a maximum allowable working pressure of 250 psig (17.24 bar/1724 kPa). They are also suitable for the delivery of gaseous product when combined with a vaporizer.
FILL The tank is filled with liquid through the FILL CONNECTION, FILL LINE CHECK VALVE, and FILL VALVES. One FILL VALVE is connected to the top of the pressure vessel and other is connected to the bottom of the of the pressure vessel. Filling through the TOP FILL VALVE tends to reduce tank pressure, while filling through the BOTTOM FILL VALVE tends to increase tank pressure. TANK BLOWDOWN VALVE can be opened for venting and throttled to maintain desired tank pressure during filling.
VALVES are open. When tank pressure decreases to the PRESSURE BUILDING REGULATOR setpoint, it opens and liquid flows from the bottom of the tank through PRESSURE BUILDING COIL. This liquid product is vaporized in the coil and expanded gaseous product returns to the top of the tank maintaining tank pressure. When tank pressure increases above the regulator’s set point it closes and the pressure building process stops.
VAPOR PHASE ISOLATION VALVE, and a bypass valve connecting the instrument lines should be installed between the isolation valves and the device. During operation this bypass valve will remain closed; its function being to equalize the pressure on each side of the differential pressure gauge. The pressure gauge will be connected to VAPOR PHASE ISOLATION VALVE so that pressure at the top of the vessel is measured.
Vacuum System Components INSTALLATION HANDLING Dimension and connection data for the GST-250 tanks can be found on the applicable General Arrangement Drawing in this manual. Additional copies of these drawings may be requested from the factory. Please include information on the tank model number and part number in making requests for this drawing. The drawing part number is listed in the applicable Specification chart in this manual. Tank installation is the customer's responsibility.
rigging equipment has adequate rated capacity to handle the tank weight listed in the specifications. This tank must be shipped and lifted empty, and with a warm inner vessel. CAUTION: To prevent possible tip over, do not leave the tank standing upright unless it is on a specified foundation or other hard surface capable of supporting its weight. Loading on the tank legs is great enough to cause them to sink into most surfaces other than reinforced concrete.
Requirements for Installation and Use Within New York City Fire Department Jurisdiction Owners and installers within NYCFD jurisdiction are required to meet the following guidelines concerning the installation and use of GST-250 design bulk tanks. • The installation and use of the vessel must comply with all applicable New York City Codes, Rules, and Regulations. • After installation, the vessel shall not be filled until the required New York City Fire Department storage permit has been issued.
RIGGING Note: Refer to General Arrangement Drawing for Critical Weight and Dimensional Data.
Note: Refer to General Arrangement Drawing for Critical Weight and Dimensional Data.
Note: Refer to General Arrangement Drawing for Critical Weight and Dimensional Data.
OPERATION These instructions are for experienced operators. Before operating the storage tank become thoroughly familiar with the safety precautions in this manual and in reference publications. Make certain all applicable provisions set forth in the Installation section have been followed before placing a tank in operation.
VALVE should be opened just before closing VAPOR & LIQUILD PHASE ISOLATION VALVES to prevent damage to the LIQUID LEVEL GAUGE. Carefully loosen the adapters on both sides of the LIQUID LEVEL GAUGE to relieve pressure. Disconnect the instrument lines and fully open VAPOR & LIQUILD PHASE ISOLATION VALVES. Visually check the resultant gas streams for signs of moisture. Vent lines for approximately two minutes. If no moisture is evident, close the VAPOR & LIQUILD PHASE ISOLATION VALVES.
NOTE: The tank was pressurized at the factory with nitrogen gas. Before the tank is to be filled with any product, it must be purged with product until analysis indicates an acceptable purity. Use the steps outlined in the Purge Procedure section above as a guide. 4. Open TANK BLOWDOWN VALVE and TRYCOCK VALVE. Vent tank pressure to about 5 psig (0.34 bar/34 kPa). Close the TANK BLOWDOWN VALVE but leave the TRYCOCK VALVE open. 5.
3. Open supply source liquid delivery valve. 4. Fully open tank BOTTOM FILL VALVE, PRESSURE BUILDING ISOLATION VALVES start tank fill. Open tank TOP FILL VALVE one turn. Adjust the two FILL VALVES as required to maintain normal tank operating pressure as shown on tag attached to tank PRESSURE GAUGE, INNER VESSEL.
PRODUCT SUPPLY VALVE, All other valves should be closed. TAKING A TANK OUT OF SERVICE Schedule shutdown operation to coincide with low liquid level in the tank. If a large quantity of liquid is in the tank, drain it into a trailer for use elsewhere or for disposal at a safe location. For tanks so equipped, small quantities of liquid can be vaporized by the PRESSURE BUILDING COIL and vented through the TANK BLOWDOWN VALVE, provided appropriate safety precautions are taken.
MAINTENANCE GENERAL The need for maintenance usually becomes apparent from inspection of the tank before filling, routine observation during and after filling, and indications of improper operation. Typical trouble indications would be unusually high or low tank or pipeline pressure, leakage from valves or piping connections, and excessive venting through relief valves. Prompt action to correct damage or malfunction is required to assure reliable operation.
CONTROL VALVES These tanks have two automatic valves that control operating pressures. The PRESSURE BUILDING REGULATOR opens on falling tank pressure and closes on rising pressure. This valve is factory set at 150 psig (10.34 bar/1034 kPa). The BACK PRESSURE REGULATOR is a backpressure device that opens on rising tank pressure and closes on falling pressure. This valve is factory set at 165 psig (11.37 bar/1137 kPa). The factory setting of the control valves may be field adjusted.
SETTING PRESSURE BUILDING REGULATOR (PCV-1): 1. If tank pressure is below desired setting: Loosen pressure screw locknut on PRESSURE REGULATOR. With PRESSURE BUILDING ISOLATION VALVES open, gradually open PRESSURE REGULATOR by turning pressure screw in (clockwise) to build tank pressure to 5 psig (0.34 bar / 34 kPa) above the desired delivery pressure. Note that the pressure screw must be adjusted in small increments, allowing sufficient time for tank pressure to stabilize each time the screw is turned.
Main TANK PRESSURE RELIEF VALVES that leak or fail to operate at the set pressure should be replaced immediately. Repair and recalibration of these valves should only be done by experienced personnel with proper equipment. Return the valves to the manufacturer or to an ASME approved repair station for overhaul or recalibration. In certain cases these valves shall be tested every five years per CGA S-1.
CASING VACUUM MAINTENANCE CHECKING VACUUM Some vacuum deterioration may occur over an extended period of time due to out gassing of materials within the vacuum space or from leakage. A history of vacuum readings taken over a period of time can be valuable when evaluating tank performance and scheduling maintenance work. To detect vacuum deterioration, periodic measurement of the tank vacuum is recommended.
VACUUM PROBE REPLACEMENT If the VACUUM PROBE TUBE is damaged or is suspected of giving inaccurate readings, replace it as follows: 1. Make certain that the VACUUM PROBE ISOLATION VALVE is closed. 2. Unscrew the VACUUM PROBE from the VACUUM PROBE ISOLATION VALVE. Using two wrenches. 3. Clean the threads and opening of the VACUUM PROBE ISOLATION VALVE. NOTE: Do not use Teflon tape as a sealant on vacuum system fittings. 4.
Try to determine the source of leakage in cases where the VACUUM JACKET LIFT PLATE has not functioned, visually inspect the following areas in the order in which they are listed: a. b. c. d. e. f. g. VACUUM PROBE, VACUUM PROBE ISOLATION VALVE, VACUUM PUMPOUT VALVE, Sealed insulation ports (on top of the tank), VACUUM JACKET LIFTPLATE, All liquid and gas phase lines exit points through vacuum jacket, Any area of the vacuum jacket that might have been exposed to cryogenic liquid spray or temperatures.
TROUBLE-REMEDY GUIDE POSSIBLE CAUSES TROUBLE 1. 2. 3. 4. 5. 6. Tank Pressure too low. Excessive tank pressure. Malfunction of Back Pressure Valve. Erratic or erroneous Liquid Level Gauge readings. Leaking safety valve. Ruptured Pressure Vessel Rupture REMEDY a. Tank Pressure Relief Valve leaking or frozen open. a. Thaw out valve or replace if necessary. Refer to Step 5, this section. b. Tank Rupture Disc rupture. b. Replace Tank Rupture Disc. Refer to Step 6, this section. c.
Disc. 7. Tank vacuum leak. Rupture Disc. b. Defective Rupture Disc. b. . Replace Rupture Disc c. Atmosphere corrosion and/or disc fatigue. c. Replace Rupture Disc d. Interior disc corrosion. d. Blow out safety device line. Replace Rupture Disc. e. Improper Rupture Disc. e. Install correct Rupture Disc. a. Leak in Vacuum Jacket Lift Plate. a. Refer to Analyzing Vacuum Deterioration section. Replace Vacuum Jacket Lift Plate. b. Vacuum Pump Out Valve leak. b.
RECOMMENDED TOOLS, EQUIPMENT, AND MATERIALS Components in the "Reference" column are provided to indicate where various tools, equipment, and material are used. For locations of various suppliers listed, refer to the Address List section.
TANK PART AND GENERAL ARRANGEMENT DRAWING NUMBERS STANDARD TANK SIZE 1500 3000 6000 9000 11000 13000 15000 MAWP PART NUMBER 250 250 250 250 250 250 250 2217405 2217407 2217408 2217410 2217411 2217412 2217413 32 GENERAL ARRANGEMENT DRAWING 2217414 2217415 2217415 2217416 2217416 2217416 2217416
4275 Hamilton Blvd Theodore, Alabama 36582 U.S.A. Telephone: (251) 443-8680 Fax: (251) 443-2209 In U.S. and Canada: (800) TW TANKS (898-2657) customerservice@taylorwharton.com http://www.taylorwharton.
