SB330-4A1/112U-330A HYDAC 4L Bladder Accumulator

Product Overview

The HYDAC SB330-4A1/112U-330A is a 4-liter standard bladder accumulator from the HYDAC SB330 series. The exact HYDAC part number is 3047166.

The accumulator is designed for high-pressure hydraulic systems requiring:

• Hydraulic energy storage
• Peak-flow support
• Shock absorption
• Pressure pulsation damping
• Leakage compensation
• Volume compensation

The HYDAC construction separates the gas side from the hydraulic-fluid side using a replaceable bladder. During charging, hydraulic fluid enters the vessel and compresses nitrogen. During a pressure drop or transient demand, the compressed gas forces hydraulic fluid back into the circuit.

According to HYDAC’s official product database, the SB330-4A1/112U-330A is rated at 330 bar, uses a 4 L nominal volume, Buna N/NBR bladder, carbon-steel shell and G1-1/4 BSPP / ISO 228 fluid connection. The standard gas connection is HYDAC Gas Valve Version 4, 8V1 / ISO 4570.

For replacement applications, the complete model code must be matched. The fluid-port configuration is especially important because HYDAC offers SB330 accumulators with BSPP, SAE and NPT connections in different configurations.

Our replacement accumulators are produced with emphasis on OEM dimensional interchangeability and undergo 100% simulated operating-condition testing for pressure retention, leakage, pre-charge stability and charge/discharge performance.

Technical Specifications (Bulleted List)

• Manufacturer: HYDAC Technology GmbH
• Series: SB330
• Product Type: Standard Bladder Accumulator
• Complete Model: SB330-4A1/112U-330A
• HYDAC Part Number: 3047166
• Nominal Volume: 4 L
• Maximum Working Pressure: 330 bar / 4786 psi
• Typical Pressure: 3000 psi
• Effective Gas Volume: 0.98 gal / 226 in³
• Bladder Compound: Buna N / NBR
• Shell Material: Carbon Steel
• Fluid Port Connection: BSPP / ISO 228
• Fluid Port Size: G1-1/4 in.
• Fluid Port Seal: Radial seal design
• Fluid Port Material: Carbon Steel
• Gas Valve: HYDAC Gas Valve Version 4, 8V1 / ISO 4570
• Line Connection: Threaded
• Maximum Discharge Flow Rate: 160 gpm
• Operating Temperature: 5°F to 180°F, approximately -15°C to +82°C
• Weight: 14 kg / 30 lb
• Repairable: Yes
• Design: Standard, bottom repairable
• Installation Certification: PED / CE
• Typical Fluid: Mineral Oil
• Accumulator Diameter: 168 mm
• Dimension A: 415 mm
• Dimension B: 66 mm
• Dimension C: 58 mm
• Dimension E: 53 mm
• Displacement: Not applicable
• Rotational Speed: Not applicable

All core data above is taken from HYDAC’s official product record for Part No. 3047166 / Model SB330-4A1/112U-330A.

Important Dimensional Verification

The original product wording includes:

22 7/8-14UNF
L = 205 mm
D = 198 mm

These values could not be verified against the official HYDAC specification for the complete SB330-4A1/112U-330A accumulator.

HYDAC officially specifies:

• Fluid connection: G1-1/4 BSPP / ISO 228
• Accumulator diameter: 168 mm
• Dimension A: 415 mm
• Gas valve: 8V1 / ISO 4570

Therefore, the 22 7/8-14UNF / 205 mm / 198 mm data should not be published as official accumulator dimensions unless separate evidence confirms that they refer to a replacement bladder or another component.

Key Technical Advantages

330 bar High-Pressure Capability

The SB330-4A1/112U-330A is rated at 330 bar / 4786 psi, making it suitable for high-pressure industrial hydraulic circuits.

4 L Energy Storage Capacity

The 4-liter nominal volume provides a compact energy-storage solution for hydraulic power units, pressure compensation and transient-flow assistance.

NBR Bladder and Carbon-Steel Shell

The standard configuration uses a Buna N/NBR bladder and carbon-steel pressure shell, a common combination for mineral-oil hydraulic systems.

Serviceable Bladder Construction

HYDAC identifies the accumulator as repairable and bottom repairable, allowing bladder and sealing components to be serviced rather than replacing the complete pressure vessel.

Fast Bladder Response

HYDAC highlights the rapid response characteristics of bladder accumulators compared with diaphragm designs, making the SB330 suitable for transient hydraulic events, shock absorption and peak-flow requirements.

High Discharge Flow Capability

HYDAC specifies a maximum discharge flow rate of 160 gpm for this exact model. The practical system flow, however, also depends on installation configuration, piping losses, valves and the charging/discharging conditions.

Standard G1-1/4 BSPP Interface

The G1-1/4 BSPP / ISO 228 fluid connection provides a standardized threaded interface for compatible hydraulic installations. HYDAC identifies this exact connection for Part No. 3047166.

Application Areas

• Hydraulic Power Units
• Hydraulic Presses
• Machine Tools
• Construction Machinery
• Agricultural Machinery
• Forestry Equipment
• Mining Equipment
• Mobile Hydraulic Systems
• Oilfield and Offshore Equipment
• Industrial Automation
• Hydraulic Test Benches
• Energy Storage Circuits
• Pressure Pulsation Damping
• Hydraulic Shock Absorption
• Leakage Compensation Systems

These applications are consistent with HYDAC’s listed SB330 application areas, including agricultural, forestry, oilfield/offshore, machine-tool, mining and mobile/construction equipment.

Expert Maintenance Tips

Calculate Nitrogen Pre-Charge Based on the Application

Do not set the nitrogen pre-charge simply from the 330 bar vessel rating.

The pre-charge must be calculated according to:

• Minimum operating pressure
• Maximum operating pressure
• Required usable oil volume
• Charging/discharging cycle
• Operating temperature
• Required response

Use Nitrogen Only

Use nitrogen for the gas side of the accumulator. Oxygen or ordinary compressed air must not be used.

Prefer Vertical Installation for Energy Storage

HYDAC recommends vertical installation with the fluid connection downward for energy-storage applications. Horizontal or angled installation can reduce the usable volume available from the accumulator.

Match the Exact Hydraulic Connection

The official connection for SB330-4A1/112U-330A is:

G1-1/4 BSPP / ISO 228

Do not substitute an SAE or NPT configuration merely because it belongs to the same SB330 family. HYDAC offers multiple connection configurations.

Inspect Bladder and Gas-Valve Components

Inspect the bladder, gas valve, O-rings and sealing surfaces if:

• Pre-charge pressure drops unexpectedly
• Hydraulic pressure fluctuates
• Stored-energy performance decreases
• Gas-side leakage is detected
• Hydraulic shock increases
• Charge/discharge behavior changes

Conduct Full Replacement Testing

For a replacement accumulator, verify:

• Vessel identification
• Nominal volume
• Pressure rating
• Bladder compound
• Hydraulic port
• Gas valve
• Nitrogen pre-charge
• Hydraulic leakage
• Gas-side leakage
• Charge/discharge performance

Our replacement units can be subjected to 100% simulated operating-condition testing before shipment to verify sealing integrity, pressure retention and hydraulic performance.