Bladder Accumulator - BA Series
The Parker bladder style accumulator is a proven design which has served both the industrial and mobile hydraulic markets, providing energy management solutions for many hydraulic system applications. Offering a standard, globally certified bladder accumulator (ASME, PED(CE), CRN, and AS1210) is Parker’s approach at one accumulator design certified for most markets, geographies and applications.
Parker’s globally certified bladder accumulator design meshes the very best of the Greer and Olaer brands. As the global leader in motion control, Parker appreciates that our customers demand one product that is available and acceptable worldwide.
We offer the broadest line of quality products, including:
• Bottom and Top Repairable designs
• 10 in³ (10 cubic inch), 1 Pint (1 pt), 1 Quart (1 qt), 150 in³ (150 cubic inch), 1 Gallon (1 G), 2-1/2 Gallon (2.5 G), 5 Gallon (5 G), 10 Gallon (10 G), 11 Gallon (11 G), and 15 Gallon (15 G) capacities
• 3,000 psi (3 KSI) to 10,000 psi (10 KSI) designs
• Global certifications (ie, ABS, ASME, AS1210, CRN, DNV, DOSH, NR-13, PED (CE), SELO, ASME app 22)
• Various gas valve designs (std Schrader, Military, poppet, High Flow, etc)
• Bladder compounds (Nitrile, Hydrin, Fluorocarbon, Butyl, EPR, etc)
• Fluid Ports (SAE, NPT, Code 61 & 62, BSPP, High Flow, etc)
• Safety Fuse Options
• Mounting, Charging, and Gauging Accessories
Parker bladder accumulator products are made to the highest quality standard and because of our in-house bladder molding operations, we offer extremely competitive lead times. The heart of any bladder accumulator is the actual rubber bladder bag, and Parker bladders are engineered and manufactured in our own facility and subjected to our own high quality inspection standards.
Why Use Bladder Accumulators?
• Highly tolerant of fluid contamination
• Very quick response time
• Works well with water, and other low lubricity fluids
• Great for high frequency, dithering applications
• Lightweight, compact construction
• Easily field repairable
• Safety; cannot be disassembled under pressure
Why Use Parker accumulators in your application?
• Improves system efficiency
• Supplements pump flow
• Supplies power in emergency
• Compensates for leakage
• Energy Conservation
• Compensates for leakage
• Noise attenuation
• Absorbs hydraulic shocks
• High/low temperature tolerance
• Wide range of compounds for a variety of fluids
Materials
• Shell – high strength alloy steel (SA372, all sizes comply with ASME material specifications, 1 gal. & larger supplied with ASME Certification as standard)
• Ports – all oil service ports, high strength alloy steel
– water & chemical service:
3000 PSI, 304 stainless steel
5000 PSI, 17-4 PH stainless steel
• Poppet & Spring – 304 stainless steel
• Gas Valve Cartridge – steel
• Gas Valve Protector – steel
• Gas Valve Stem – steel
• Bladders – various elastomers, see Standard and Optional Bladders in this section.
Pressure Ratings:
• 3000 psi (4:1 design) & 330 bar Bottom Repairable (Under 1 Gallon)
• 3000 psi ASME, 4000 psi ASME App 22, & 330 bar (4,785 psi) PED Bottom Repairable (1 G)
• 3000 psi ASME, 3600 psi ASME App 22, & 330 bar (4,785 psi) PED Bottom Repairable (2.5 G to 15 G)
• 3000 psi ASME, 3600 psi ASME App 22, & 330 bar (4,785 psi) PED Top Repairable (2.5 G to 15 G)
• 5000 psi ASME, 6600 psi ASME App 22, & 690 bar (10,000 psi) PED Bottom Repairable (1 G to 15 G)
• 5000 psi ASME, 6600 psi ASME App 22, & 690 bar (10,000 psi) PED Top Repairable (2.5 G to 15 G)
• 3000 psi High-flow
Precharge:
Units are shipped with a nominal nitrogen pre-charge as standard. For specific precharge pressures, specify at the time of order.
Max. Recommended Compression Ratio (max. working pressure/pre charge pressure): 4 to 1.
Fluids – bladder accumulators are compatible with a wide variety of fluids. The standard accumulator may be used with petroleum-based industrial or water-based flame resistant fluids. Bladders compatible with most industrial fluids can be furnished on special orders with temperature ranges from -40°F to 250°F (-40°C to 121°C).
Available Options – a wide variety of options are available on Parker bladder accumulators including:
• Bladder Compounds
• Fluid Ports
• Water & Chemical Service
• Gas Valves
• Rupture Disks, Burst Disks, and Safety Fuse Assemblies
• Fixed mount gauge adapters
• Remote monitoring precharge pressure
• Pressure Gauges
Components of a Bladder Accumulator:
Shell:
Bladder accumulator shells are made from chrome-molybdenum alloy steel (SA372) with forged ends. All sizes comply with ASME/PED material and design specifications. One gallon and larger accumulators are supplied with ASME and PED certifications as standard. Stainless steel and exotic metal shells are available upon request.
Bladder:
Polymer bladders are manufactured in-house to control the material blending, molding, critical seam assembly, and curing processes. It is widely accepted that Parker bladder designs are the highest quality bladders in the industry. Bladders are offered in five different standard compounds to suit a wide variety of fluids and operating temperatures. Special compounds are available for extreme, unusual or severe applications.
Bladder Stems:
All bladder accumulators, sizes 1 gallon and larger, are fitted as standard with two-piece bladder stems with replaceable gas valve cartridge for ease of serviceability. Also, the two piece stem will accept high-flow poppet type gas valves and permanent mount gauge adapters.
Port Assemblies:
Standard oil service ports are made from high-strength alloy steel for maximum durability. Chemical and water service port assemblies are made from electroless nickel plated or stainless steel materials for maximum corrosion resistance.
Fluid Ports:
SAE straight thread, NPTF, SAE Code 61 and SAE Code 62 4-bolt split flange, and High-flow ports are available. Bleed ports are included as standard on sizes 1 gallon and larger; not available on flange ports.
Gas Valve:
All accumulators are fitted with a gas valve for ease of gas pre-charging. One-gallon and larger 3000 PSI units are equipped with a cored gas valve cartridge (ISO-4570-8V1) for ease of maintenance. 5000 PSI units are equipped with a high pressure cored gas valve cartridge with an option of a high-flow poppet gas valve cartridge (L07689000K). For safety, the gas valve vents if unscrewed.
Types of Bladder Accumulators:
Bottom Repairable design, due to its simplicity and cost effectiveness, has become the de facto “Industry Standard” bladder accumulator. Sizes range from 10 cu in to 15 gallons.
The Top Repairable Accumulator permits easy checking and maintenance of the bladder without removing the accumulator from the service line, saving time and money. Sizes range from 2.5 G to 15 G.
For systems requiring a fast discharge or “dumping” rate, the High-flow accumulator incorporates a large port assembly capable of flows up to 600 GPM (2270 LPM). Sizes range from 2-1/2 to 15 gallons.
Standard and Optional Bladders:
A variety of bladders are offered to suit a wide range of fluids and operating temperatures. The following table lists the optional bladders available, their recommended operating temperature ranges, and the types of fluids that are generally compatible.
Bladder Compounds:
Nitrile (Buna-N)
Hydrin (Low Temp)
Butyl (compatible with phosphate ester fluids)
Ethylene Propylene (EPR/EPDM)
Fluorocarbon
Water & Chemical Service Options (W)
Bladder accumulators are available with a water and chemical resistance option. The (W) designation includes an internally Scotchkoted shell and stainless steel or electroless nickel plated port assembly. The Skotchkote offers added protection against more corrosive fluids.
Gas Valves
Two types of gas valves are available on bladder accumulators. 3000 PSI rated models are offered with a cored gas valve cartridge (cartridge type, 1 gal. & up, ISO-4570-8V1) as standard. 5000 PSI units are equipped with a high-pressure cored gas valve cartridge with an option of a heavy-duty poppet type gas valve cartridge (L07689000K). A high-flow poppet style gas valve is available upon request, but must be approved by a Parker accumulator engineer. Please contact the division for assistance.
Standard and Optional Fluid Ports
Both standard and optional fluid ports are offered on all Bottom Repairable, Top Repairable, and Transfer Barrier accumulators.
Safety Fuse Options
Safety Fuses are used as a safety device on accumulators and gas bottles to prevent over-pressurization of gas due to external heat or hydraulic pressure (set at 140% of maximum system pressure to avoid rupture disk fatigue and premature failure). The rupture disks are calibrated to rupture at a predetermined pressure. Safety fuses are available on most sizes of piston and bladder accumulators and gas bottles. Safety fuses can be installed on 1 gallon & larger accumulators by using the “Fuse Adapter” as shown to the right. The thermal fuse assembly and/or fuse adapter must be ordered separately.
Special Options
If your application requires a bladder accumulator or special option that falls outside of our broad offering, consult your local distributor, Parker application engineer or field sales representative, or the factory with your specific requirements. We have the manufacturing and engineering expertise to design and build bladder accumulators to your exacting requirements, from simple modifications to standard units to complete designs from scratch. Some example of our past special designs include:
• Special and Stainless Steel Materials
• Special Bladder Compounds
• Suction Stabilizer
• Pulsation Dampener
• Special Certifications
Consult our experts with your next bladder accumulator requirement!
Certifications for Global Requirements
Certifications for accumulators vary – often quite significantly – depending upon the application or industry in which will be used and/or the country they will be used in. Sorting through and understanding the myriad of requirements that may be encountered is a daunting and difficult task. A truly global certification standard, meanwhile, remained all but impossible to achieve due to the parameters that must be met for individual country regulations.
Parker’s Accumulator & Cooler Division engineers have extensively researched and fully understand these pressure vessel codes. From the United States to Europe, Asia and Australia, our experts are ready and able to help you avoid the many costly and time consuming pitfalls you didn’t see coming. Furthermore, ACD can provide the global accumulator certifications you need.
Parker ACD now offers global certified ASME/CE/CRN/AS1210 bladder accumulators as standard on 1 gallon and larger sizes. As the global leader in motion control, Parker appreciates that our customers demand one product that is available and acceptable worldwide. No matter where you need to be, Parker’s Accumulator & Cooler Division will be there to support you with the necessary products, services and global certifications.
Accumulators and gas bottles are pressure vessels that are subject to safety laws, regulations, and ordinances that are valid in the state or country of installation. Other particular regulations must be observed in certain industries such as mining, shipbuilding and aircraft. This brief will discuss the two fundamental design codes and several of the most common certifications. Since many more certifications exist, we recommend contacting Parker’s Accumulator & Cooler Division engineers to ensure proper conformance to those standards.
Two Base Design Codes
While many countries and manufacturers have their own regulations and quality standards for hydraulic accumulators, most refer back to one of two base design codes. The oldest and most referenced design code for pressure vessels is ASME. Originally written to create a standard for the manufacture of boilers on steam locomotives, the American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code Section VIII, Division 1 has evolved into requirements for unfired pressure vessels and accumulators in the United States. This section requires the following:
1. Certification on vessels with internal diameters of 6" or greater.
2. Certified vessels carry the “U” symbol on them as evidence that they were designed and manufactured in accordance with the Code. The “U” symbol is an internationally recognized symbol of design and manufacturing quality.
3. Accumulators must be manufactured from materials that meet ASME specifications for traceability.
4. A design factor of 3.5:1 in the ratio of minimum burst pressure to rated pressure. All design factors are with respect to the specified minimum tensile strength of the material. 3.5:1 is specific for a seamless shell design as those used for the bladder accumulators.
5. ASME requires that each vessel be marked with the design pressure at the Minimum Design Metal
Temperature (MDMT) for the vessel.
6. Surveillance of an approved quality system, like ISO 9001.
7. All hydrostatic testing to be witnessed by a recognized authorized inspection agency. The 3.5:1 design factor requirement is mandatory for all accumulators with ASME Certification with the exception of those that comply with a specific rule within the Code called “Appendix 22.” Appendix 22 permits that accumulators manufactured with “forged” shells and with openings of a specified maximum size may be certified with a design factor of 3:1 in the ratio of burst pressure to rated pressure. This includes bladder style accumulators.
The second base design code is the European Pressure Equipment Directive. In May 2002, the Directive
97/23/EC (Pressure Equipment Directive) came into regulation in the European Union. This directive applies to the design, manufacture, testing and conformity assessment of pressure equipment and assemblies of pressure equipment that operate over 0.5 bar. The directive requires the following:
1. The operating fluids must be in Group 2 (non-hazardous).
2. Certified vessels with a volume greater than 1 liter gas capacity must be CE marked.
3. Certified vessels must be manufactured from materials that meet PED specifications for traceability.
4. Certified product must pass a low temperature Charpy test (temperature to be determined by application or customer).
5. Surveillance of an approved quality system, such as ISO 9001.
6. All hydrostatic testing to be witnessed by an approved notified body. Parker holds module H1 certification – allowing us to self-certify accumulators saving our customers time and money.
7. Once installed, equipment and accumulator inspection as well as operational safety are controlled by national laws.
Accumulators with a volume less than 1 liter, of gas capacity, fall within the guidelines of Sound Engineering Practice (SEP). Accumulators built to SEP must be built to a known standard and have an approved notified body approve the design and the technical file. These accumulators do not carry a CE marking.
Country Certifications
Below is a brief list of the most popular country standards that Parker ACD can provide:
1. Canada: Canadian Registration Numbers (CRN) can be obtained by constructing an accumulator from ASME-certified material using ASME standards of design then applying for the registration number. Each province has its own registration number, thus the end destination of the accumulator must be known. Some provinces are allowing alternative design codes like the PED for specific markets such as farming and mining. CRN is standard on 1gallon and larger bladder accumulators. Contact Parker ACD for detailed specifics.
2. Australia: AS1210 is a standard based on ASME design requirements. Additional hydrostatic testing is required. The accumulator must be tested at 1.5 times the design pressure for 30 minutes plus an additional 1 minute per mm of thickness of the shell/vessel. AS1210 is standard on 1gallon and larger bladder accumulators.
3. China: Accumulators shipped to China often require Special Equipment Licensing Office (SELO) approval. China currently accepts both PED and ASME design standards. To manufacture accumulators for the Chinese marketplace, a manufacturing license is required. Paperwork both before and after the purchase of the accumulator is required for submittal to China for tracking purposes.
4. Russia: Accumulators shipped to Russia often require CUTR approval. CUTR currently accepts both PED and ASME design standards. A technical file called a “passport” must be submitted with each accumulator shipment.
5. Brazil: The Regulatory Rule NR-13 establishes the minimum conditions for the installation, operation, maintenance and inspection of pressure vessels and boilers in Brazil. Both ASME and the PED are acceptable design codes, but ASME designs are more prevalent. When NR-13 is required, Parker’s engineers can submit a technical file to Brazilian Registered Engineers (BRE) for approval. After approval, an inspection at the place of installation will be performed by the BRE. This could also include hydrostatic testing.
Industry/Market Standards
1. American Bureau of Shipping (ABS): Is required for accumulators installed on shipping vessels and oil rigs. To be added to a Product Design Assessment Certificate, accumulators must meet ASME design requirements plus any additional ABS requirements. Parker has an ABS Certificate of Manufacturing Assessment and many accumulators are listed on the Bureau’s List of Type Approved Products. All ABS approved accumulators must be witness tested at Parker by an ABS inspector.
2. Det Norske Veritas (DNV): Off-shore Standard DNVOS-E101 is often required for accumulators on off-shore oil and gas applications, particularly in the North Sea. Many of Parker’s accumulators have DNV Type Approval.
Parker ACD is proud to offer dual-certified ASME/CE bladder accumulators (along with CRN/AS1210), a design which meshes the very best of the Greer and Olaer brands. As the global leader in motion control, Parker appreciates that our customers demand one product that is available and acceptable worldwide. No matter where you need to be, Parker’s Accumulator & Cooler Division will be there to support you with the necessary products, services and global certifications.
Parker’s globally certified bladder accumulator design meshes the very best of the Greer and Olaer brands. As the global leader in motion control, Parker appreciates that our customers demand one product that is available and acceptable worldwide.
We offer the broadest line of quality products, including:
• Bottom and Top Repairable designs
• 10 in³ (10 cubic inch), 1 Pint (1 pt), 1 Quart (1 qt), 150 in³ (150 cubic inch), 1 Gallon (1 G), 2-1/2 Gallon (2.5 G), 5 Gallon (5 G), 10 Gallon (10 G), 11 Gallon (11 G), and 15 Gallon (15 G) capacities
• 3,000 psi (3 KSI) to 10,000 psi (10 KSI) designs
• Global certifications (ie, ABS, ASME, AS1210, CRN, DNV, DOSH, NR-13, PED (CE), SELO, ASME app 22)
• Various gas valve designs (std Schrader, Military, poppet, High Flow, etc)
• Bladder compounds (Nitrile, Hydrin, Fluorocarbon, Butyl, EPR, etc)
• Fluid Ports (SAE, NPT, Code 61 & 62, BSPP, High Flow, etc)
• Safety Fuse Options
• Mounting, Charging, and Gauging Accessories
Parker bladder accumulator products are made to the highest quality standard and because of our in-house bladder molding operations, we offer extremely competitive lead times. The heart of any bladder accumulator is the actual rubber bladder bag, and Parker bladders are engineered and manufactured in our own facility and subjected to our own high quality inspection standards.
Why Use Bladder Accumulators?
• Highly tolerant of fluid contamination
• Very quick response time
• Works well with water, and other low lubricity fluids
• Great for high frequency, dithering applications
• Lightweight, compact construction
• Easily field repairable
• Safety; cannot be disassembled under pressure
Why Use Parker accumulators in your application?
• Improves system efficiency
• Supplements pump flow
• Supplies power in emergency
• Compensates for leakage
• Energy Conservation
• Compensates for leakage
• Noise attenuation
• Absorbs hydraulic shocks
• High/low temperature tolerance
• Wide range of compounds for a variety of fluids
Materials
• Shell – high strength alloy steel (SA372, all sizes comply with ASME material specifications, 1 gal. & larger supplied with ASME Certification as standard)
• Ports – all oil service ports, high strength alloy steel
– water & chemical service:
3000 PSI, 304 stainless steel
5000 PSI, 17-4 PH stainless steel
• Poppet & Spring – 304 stainless steel
• Gas Valve Cartridge – steel
• Gas Valve Protector – steel
• Gas Valve Stem – steel
• Bladders – various elastomers, see Standard and Optional Bladders in this section.
Pressure Ratings:
• 3000 psi (4:1 design) & 330 bar Bottom Repairable (Under 1 Gallon)
• 3000 psi ASME, 4000 psi ASME App 22, & 330 bar (4,785 psi) PED Bottom Repairable (1 G)
• 3000 psi ASME, 3600 psi ASME App 22, & 330 bar (4,785 psi) PED Bottom Repairable (2.5 G to 15 G)
• 3000 psi ASME, 3600 psi ASME App 22, & 330 bar (4,785 psi) PED Top Repairable (2.5 G to 15 G)
• 5000 psi ASME, 6600 psi ASME App 22, & 690 bar (10,000 psi) PED Bottom Repairable (1 G to 15 G)
• 5000 psi ASME, 6600 psi ASME App 22, & 690 bar (10,000 psi) PED Top Repairable (2.5 G to 15 G)
• 3000 psi High-flow
Precharge:
Units are shipped with a nominal nitrogen pre-charge as standard. For specific precharge pressures, specify at the time of order.
Max. Recommended Compression Ratio (max. working pressure/pre charge pressure): 4 to 1.
Fluids – bladder accumulators are compatible with a wide variety of fluids. The standard accumulator may be used with petroleum-based industrial or water-based flame resistant fluids. Bladders compatible with most industrial fluids can be furnished on special orders with temperature ranges from -40°F to 250°F (-40°C to 121°C).
Available Options – a wide variety of options are available on Parker bladder accumulators including:
• Bladder Compounds
• Fluid Ports
• Water & Chemical Service
• Gas Valves
• Rupture Disks, Burst Disks, and Safety Fuse Assemblies
• Fixed mount gauge adapters
• Remote monitoring precharge pressure
• Pressure Gauges
Components of a Bladder Accumulator:
Shell:
Bladder accumulator shells are made from chrome-molybdenum alloy steel (SA372) with forged ends. All sizes comply with ASME/PED material and design specifications. One gallon and larger accumulators are supplied with ASME and PED certifications as standard. Stainless steel and exotic metal shells are available upon request.
Bladder:
Polymer bladders are manufactured in-house to control the material blending, molding, critical seam assembly, and curing processes. It is widely accepted that Parker bladder designs are the highest quality bladders in the industry. Bladders are offered in five different standard compounds to suit a wide variety of fluids and operating temperatures. Special compounds are available for extreme, unusual or severe applications.
Bladder Stems:
All bladder accumulators, sizes 1 gallon and larger, are fitted as standard with two-piece bladder stems with replaceable gas valve cartridge for ease of serviceability. Also, the two piece stem will accept high-flow poppet type gas valves and permanent mount gauge adapters.
Port Assemblies:
Standard oil service ports are made from high-strength alloy steel for maximum durability. Chemical and water service port assemblies are made from electroless nickel plated or stainless steel materials for maximum corrosion resistance.
Fluid Ports:
SAE straight thread, NPTF, SAE Code 61 and SAE Code 62 4-bolt split flange, and High-flow ports are available. Bleed ports are included as standard on sizes 1 gallon and larger; not available on flange ports.
Gas Valve:
All accumulators are fitted with a gas valve for ease of gas pre-charging. One-gallon and larger 3000 PSI units are equipped with a cored gas valve cartridge (ISO-4570-8V1) for ease of maintenance. 5000 PSI units are equipped with a high pressure cored gas valve cartridge with an option of a high-flow poppet gas valve cartridge (L07689000K). For safety, the gas valve vents if unscrewed.
Types of Bladder Accumulators:
Bottom Repairable design, due to its simplicity and cost effectiveness, has become the de facto “Industry Standard” bladder accumulator. Sizes range from 10 cu in to 15 gallons.
The Top Repairable Accumulator permits easy checking and maintenance of the bladder without removing the accumulator from the service line, saving time and money. Sizes range from 2.5 G to 15 G.
For systems requiring a fast discharge or “dumping” rate, the High-flow accumulator incorporates a large port assembly capable of flows up to 600 GPM (2270 LPM). Sizes range from 2-1/2 to 15 gallons.
Standard and Optional Bladders:
A variety of bladders are offered to suit a wide range of fluids and operating temperatures. The following table lists the optional bladders available, their recommended operating temperature ranges, and the types of fluids that are generally compatible.
Bladder Compounds:
Nitrile (Buna-N)
Hydrin (Low Temp)
Butyl (compatible with phosphate ester fluids)
Ethylene Propylene (EPR/EPDM)
Fluorocarbon
Water & Chemical Service Options (W)
Bladder accumulators are available with a water and chemical resistance option. The (W) designation includes an internally Scotchkoted shell and stainless steel or electroless nickel plated port assembly. The Skotchkote offers added protection against more corrosive fluids.
Gas Valves
Two types of gas valves are available on bladder accumulators. 3000 PSI rated models are offered with a cored gas valve cartridge (cartridge type, 1 gal. & up, ISO-4570-8V1) as standard. 5000 PSI units are equipped with a high-pressure cored gas valve cartridge with an option of a heavy-duty poppet type gas valve cartridge (L07689000K). A high-flow poppet style gas valve is available upon request, but must be approved by a Parker accumulator engineer. Please contact the division for assistance.
Standard and Optional Fluid Ports
Both standard and optional fluid ports are offered on all Bottom Repairable, Top Repairable, and Transfer Barrier accumulators.
Safety Fuse Options
Safety Fuses are used as a safety device on accumulators and gas bottles to prevent over-pressurization of gas due to external heat or hydraulic pressure (set at 140% of maximum system pressure to avoid rupture disk fatigue and premature failure). The rupture disks are calibrated to rupture at a predetermined pressure. Safety fuses are available on most sizes of piston and bladder accumulators and gas bottles. Safety fuses can be installed on 1 gallon & larger accumulators by using the “Fuse Adapter” as shown to the right. The thermal fuse assembly and/or fuse adapter must be ordered separately.
Special Options
If your application requires a bladder accumulator or special option that falls outside of our broad offering, consult your local distributor, Parker application engineer or field sales representative, or the factory with your specific requirements. We have the manufacturing and engineering expertise to design and build bladder accumulators to your exacting requirements, from simple modifications to standard units to complete designs from scratch. Some example of our past special designs include:
• Special and Stainless Steel Materials
• Special Bladder Compounds
• Suction Stabilizer
• Pulsation Dampener
• Special Certifications
Consult our experts with your next bladder accumulator requirement!
Certifications for Global Requirements
Certifications for accumulators vary – often quite significantly – depending upon the application or industry in which will be used and/or the country they will be used in. Sorting through and understanding the myriad of requirements that may be encountered is a daunting and difficult task. A truly global certification standard, meanwhile, remained all but impossible to achieve due to the parameters that must be met for individual country regulations.
Parker’s Accumulator & Cooler Division engineers have extensively researched and fully understand these pressure vessel codes. From the United States to Europe, Asia and Australia, our experts are ready and able to help you avoid the many costly and time consuming pitfalls you didn’t see coming. Furthermore, ACD can provide the global accumulator certifications you need.
Parker ACD now offers global certified ASME/CE/CRN/AS1210 bladder accumulators as standard on 1 gallon and larger sizes. As the global leader in motion control, Parker appreciates that our customers demand one product that is available and acceptable worldwide. No matter where you need to be, Parker’s Accumulator & Cooler Division will be there to support you with the necessary products, services and global certifications.
Accumulators and gas bottles are pressure vessels that are subject to safety laws, regulations, and ordinances that are valid in the state or country of installation. Other particular regulations must be observed in certain industries such as mining, shipbuilding and aircraft. This brief will discuss the two fundamental design codes and several of the most common certifications. Since many more certifications exist, we recommend contacting Parker’s Accumulator & Cooler Division engineers to ensure proper conformance to those standards.
Two Base Design Codes
While many countries and manufacturers have their own regulations and quality standards for hydraulic accumulators, most refer back to one of two base design codes. The oldest and most referenced design code for pressure vessels is ASME. Originally written to create a standard for the manufacture of boilers on steam locomotives, the American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code Section VIII, Division 1 has evolved into requirements for unfired pressure vessels and accumulators in the United States. This section requires the following:
1. Certification on vessels with internal diameters of 6" or greater.
2. Certified vessels carry the “U” symbol on them as evidence that they were designed and manufactured in accordance with the Code. The “U” symbol is an internationally recognized symbol of design and manufacturing quality.
3. Accumulators must be manufactured from materials that meet ASME specifications for traceability.
4. A design factor of 3.5:1 in the ratio of minimum burst pressure to rated pressure. All design factors are with respect to the specified minimum tensile strength of the material. 3.5:1 is specific for a seamless shell design as those used for the bladder accumulators.
5. ASME requires that each vessel be marked with the design pressure at the Minimum Design Metal
Temperature (MDMT) for the vessel.
6. Surveillance of an approved quality system, like ISO 9001.
7. All hydrostatic testing to be witnessed by a recognized authorized inspection agency. The 3.5:1 design factor requirement is mandatory for all accumulators with ASME Certification with the exception of those that comply with a specific rule within the Code called “Appendix 22.” Appendix 22 permits that accumulators manufactured with “forged” shells and with openings of a specified maximum size may be certified with a design factor of 3:1 in the ratio of burst pressure to rated pressure. This includes bladder style accumulators.
The second base design code is the European Pressure Equipment Directive. In May 2002, the Directive
97/23/EC (Pressure Equipment Directive) came into regulation in the European Union. This directive applies to the design, manufacture, testing and conformity assessment of pressure equipment and assemblies of pressure equipment that operate over 0.5 bar. The directive requires the following:
1. The operating fluids must be in Group 2 (non-hazardous).
2. Certified vessels with a volume greater than 1 liter gas capacity must be CE marked.
3. Certified vessels must be manufactured from materials that meet PED specifications for traceability.
4. Certified product must pass a low temperature Charpy test (temperature to be determined by application or customer).
5. Surveillance of an approved quality system, such as ISO 9001.
6. All hydrostatic testing to be witnessed by an approved notified body. Parker holds module H1 certification – allowing us to self-certify accumulators saving our customers time and money.
7. Once installed, equipment and accumulator inspection as well as operational safety are controlled by national laws.
Accumulators with a volume less than 1 liter, of gas capacity, fall within the guidelines of Sound Engineering Practice (SEP). Accumulators built to SEP must be built to a known standard and have an approved notified body approve the design and the technical file. These accumulators do not carry a CE marking.
Country Certifications
Below is a brief list of the most popular country standards that Parker ACD can provide:
1. Canada: Canadian Registration Numbers (CRN) can be obtained by constructing an accumulator from ASME-certified material using ASME standards of design then applying for the registration number. Each province has its own registration number, thus the end destination of the accumulator must be known. Some provinces are allowing alternative design codes like the PED for specific markets such as farming and mining. CRN is standard on 1gallon and larger bladder accumulators. Contact Parker ACD for detailed specifics.
2. Australia: AS1210 is a standard based on ASME design requirements. Additional hydrostatic testing is required. The accumulator must be tested at 1.5 times the design pressure for 30 minutes plus an additional 1 minute per mm of thickness of the shell/vessel. AS1210 is standard on 1gallon and larger bladder accumulators.
3. China: Accumulators shipped to China often require Special Equipment Licensing Office (SELO) approval. China currently accepts both PED and ASME design standards. To manufacture accumulators for the Chinese marketplace, a manufacturing license is required. Paperwork both before and after the purchase of the accumulator is required for submittal to China for tracking purposes.
4. Russia: Accumulators shipped to Russia often require CUTR approval. CUTR currently accepts both PED and ASME design standards. A technical file called a “passport” must be submitted with each accumulator shipment.
5. Brazil: The Regulatory Rule NR-13 establishes the minimum conditions for the installation, operation, maintenance and inspection of pressure vessels and boilers in Brazil. Both ASME and the PED are acceptable design codes, but ASME designs are more prevalent. When NR-13 is required, Parker’s engineers can submit a technical file to Brazilian Registered Engineers (BRE) for approval. After approval, an inspection at the place of installation will be performed by the BRE. This could also include hydrostatic testing.
Industry/Market Standards
1. American Bureau of Shipping (ABS): Is required for accumulators installed on shipping vessels and oil rigs. To be added to a Product Design Assessment Certificate, accumulators must meet ASME design requirements plus any additional ABS requirements. Parker has an ABS Certificate of Manufacturing Assessment and many accumulators are listed on the Bureau’s List of Type Approved Products. All ABS approved accumulators must be witness tested at Parker by an ABS inspector.
2. Det Norske Veritas (DNV): Off-shore Standard DNVOS-E101 is often required for accumulators on off-shore oil and gas applications, particularly in the North Sea. Many of Parker’s accumulators have DNV Type Approval.
Parker ACD is proud to offer dual-certified ASME/CE bladder accumulators (along with CRN/AS1210), a design which meshes the very best of the Greer and Olaer brands. As the global leader in motion control, Parker appreciates that our customers demand one product that is available and acceptable worldwide. No matter where you need to be, Parker’s Accumulator & Cooler Division will be there to support you with the necessary products, services and global certifications.
