Cryogenics
Overview
CASHMAN | Preload Cryogenics (CPC), part of the Preload International family of companies, has been pioneering the research, development, design, and construction of prestressed, precast, sliding base concrete tanks for over half a century. Since 1952, Preload has designed and constructed more than two-dozen low temperature and cryogenic storage tanks and many more dike walls for the storage of LNG, LPG, LOX, and Ammonia, Preload has been recognized as the forerunner in the engineering and construction of circular prestressed concrete structures.
Many of the storage challenges our customers present to us today are challenges we have conquered throughout our many years in business. Preload first developed the technology/methodology and is the only company to have successfully designed and constructed prestressed concrete tanks for use as primary containment
Interest and investment in cryogenic tanks have been increasing in the past decade. As energy prices rise, the need for safe, reliable storage is increasing. CPC’s prestressed concrete tanks provide the durability, flexibility, and safety to store today’s refrigerated and cryogenic liquids, such as LNG, liquid oxygen, liquefied petroleum gas, ethylene, ammonia, and other natural gas liquids (NGLs), for a wide range of storage volumes— from 5,000 to 300,000 cubic meters (m3).
Composite Concrete Cryogenic Walls
CPC concrete walls are constructed of prestressed concrete panels that are vertically prestressed and circumferentially wrapped with prestress wires encased in shotcrete. A non-structural carbon steel liner, its sole function to provide a liquid and vapor barrier, lies between the precast, prestressed panels and the shotcrete layer. The liner is maintained in biaxial compression and not in direct contact with the LNG, which makes it less susceptible to thermal shock.
The insulation, equipment support structures, and mechanical equipment are the same as for a conventional 9% nickel (Ni) steel tank with a long track record of reliable performance. Tank commissioning, such as hydrostatic testing, pressure and vacuum testing, purging and drying, and cooldown, follows well-defined procedures similar to those used for conventional 9% Ni tanks.
Robust Concrete Construction
The precast wall connects to the roof via a cast-in-place ring beam. The roof consists of a robust concrete dome with a carbon steel liner and a suspended ceiling for the roof insulation. Roof detailing is similar to that for conventional tanks.
The robust concrete wall of the primary containment tank can take out-of-plane bending loads and is not susceptible to buckling, such as elephant-foot buckling, that steel inner tanks face. Once the wall panels are fully integrated by wire wrapping, the concrete wall can sustain the full wind load without bracing. No resilient blanket is needed to protect the concrete wall from buckling under the pressure of the settling perlite insulation in the annular space.
The bottom of the walls can move radially and, thus, avoid building up constraining forces at the wall/foundation joint. This is in contrast to conventional cast-in-place secondary tank walls that are monolithically connected with the base slab and need to be designed for large constraining loads during a spill. As a result, conventional monolithic wall connections need a thermal corner protection (TCP) to control cracking in this area. A precast concrete wall with sliding support does not need TCP. Resistance to circumferential shear and wall uplift is provided by a combination of shear lugs and restraining cables that allow the wall to slide radially but constrain it in vertical and circumferential direction.
The shotcrete layer on the tank exterior provides a durable concrete surface. The outer shotcrete layer may be reinforced with fibers or provided with an additional insulation layer to improve the wall’s resistance to external fire and missile impact.
Why Choose CPC?
A ROBUST, FULL-CONTAINMENT STORAGE SOLUTION FOR REFRIGERATED GASES
The CPC tank provides full-containment storage for refrigerated and cryogenic liquids, such as:
- LNG
- LOX
- LPG
- Ethylene
- Ammonia
DURABLE CONCRETE WALLS PROVIDE PRICE STABILITY OVER CONVENTIONAL NICKEL TANKS
The CPC tank is constructed of prefabricated wall modules that are integrated to build strong liquid and gas-tight primary and secondary containment walls. The walls are designed to maximize the use of conventional construction materials, such as concrete, post-tensioning strand/wire, and carbon steel, to minimize the use of the costly 9 percent nickel steel (9% Ni).
MODULAR CONSTRUCTION TO REDUCE ON-SITE CONSTRUCTION COST AND RISK
The modular construction of the CPC system utilizes wall elements that are prefabricated off site, significantly reducing on-site labor and increasing the quality of the wall construction. Modular construction also reduces the on-site construction schedule, reduces the environmental impact during construction, enhances construction safety, and opens construction to a wider labor market.
PROVEN CONCRETE TECHNOLOGY FOR SAFE AND RELIABLE LNG STORAGE
Precast concrete tanks for the storage of LNG were designed and constructed by CPC dating back to the 1960s, and several tanks have been in continuous service for nearly 50 years, demonstrating the durability and longevity of such tanks. The CPC design takes advantage of the experience from concrete LNG tanks built before 1980 that are still in service today. Furthermore, the design follows the most up-to-date applicable codes by American Concrete Institute (ACI) and the American Petroleum Institute to meet National Fire Protection Association (NFPA) 59A.
CLEAR PATHWAY THROUGH REGULATORY FILING AND REVIEW
The Federal Energy Regulatory Commission (FERC) and the Pipeline and Hazardous Material Safety Administration (PHMSA) are familiar with the CPC design and a clear pathway exists to get a tank through regulatory filing without delay. Following a three- month review of a typical tank design and a code comparison study, PHMSA issued a letter stating that it "...has no objection to the use of precast all-concrete storage tanks, provided that they are designed, fabricated, and constructed according to the ACI 376 standard." In May 2020, the Federal Energy Regulatory Commission.
Precast, Prestressed Concrete Tank Installations for Cryogenic Liquid Storage:
| Location | Year Built | Original Owner | Size m3 | Product | Storage Type |
|---|---|---|---|---|---|
| Nantes, France | 1965 | Gas de France | 2,000 | LNG | MEMBRANE |
| Barcelona, Spain | 1968 | Esso Research (ENAGAS) | 2 x 40,000 | LNG | SINGLE |
| South Yarmouth, MA, USA | 1973 | Buzzard's Bay Gas Co. | 8,700 | LNG | MEMBRANE |
| Philadelphia, PA, USA | 1974 | Philadelphia Gas Works | 2 x 94,000 | LNG | DOUBLE |
| Staten Island, NY, USA | 1974 | Distrigas | 2 x 143,000 | LNG | FULL |
| Winnipeg, Manitoba, Canada | 1975 | Greater Winnipeg Gas | 40,000 | LPG | SINGLE |
| Cumberland, RI, USA | 1975 | Valley Gas Co. | 4,000 | LNG | MEMBRANE |
| Barcelona, Spain | 1980 | ENAGAS | 80,000 | LNG | FULL |
| Steelton, PA, USA | 2016 | UGI | 7,500 | LNG | FULL (outer wall only) |
| Fairbanks, AK, USA | 2019 | Fairbanks Natural Gas (FNG) | 20,000 | LNG | FULL |
| Bethlehem, PA, USA | 2020 | UGI | 7,500 | LNG | FULL (outer wall only) |