Back Pressure Regulators (BPRs)

Idex Back Pressure Regulators

IDEX Back Pressure Regulators (BPRs) are designed to improve chromatographic system performance by maintaining consistent downstream pressure, helping prevent outgassing and enhancing pump check valve efficiency. These regulators are commonly used in HPLC, UHPLC, LC-MS, and multi-detector workflows where stable pressure control is essential for accurate, reproducible results.

Chrom Tech offers a complete selection of BPR assemblies, cartridges, holders, adjustable high-pressure regulators, and ultra-low volume BPRs. Available configurations include fixed-pressure assemblies at 5 and 20 psi, factory-preset cartridges and assemblies spanning 40 to 1,000 psi (2.8 to 69 bar), and high-pressure adjustable BPRs supporting operating ranges between 2,000 and 5,000 psi. Ultra-low volume models—set to 100 or 500 psi—feature swept volumes as low as 6 µL, making them ideal for sensitive multi-detector and low-dispersion applications.

BPR Assemblies are available in both biocompatible and stainless steel configurations. Biocompatible assemblies utilize a PEEK holder, polymer fittings, and chemically resistant cartridges, while stainless steel assemblies combine the same biocompatible cartridges with a 316 stainless steel holder for added durability. Each assembly includes a factory preset cartridge (except 5 and 20 psi versions) and is designed to deliver consistent incremental back pressure across typical analytical flow rates.

BPR Cartridges are manufactured from PEEK, Tefzel® (ETFE), perfluoroelastomer, and gold-plated stainless steel for broad chemical compatibility. These replacement cartridges operate across recommended flow rates of 0.1–10 mL/min, maintaining pressure stability within ±10% under normal conditions. They are fully interchangeable with standard IDEX BPR holders, allowing flexible system configuration and easy pressure adjustments.

Back Pressure Regulator Holders accept any compatible replacement cartridge and ship with fittings for 1/16" OD tubing. Select holders are surface-treated to prevent galling, ensuring smooth operation during installation. For optimal performance, cartridges are designed to reach their rated pressure when tightened to approximately 20 in-lbs of torque, which can be achieved by finger tightening followed by an additional 1/8–1/4 turn using the supplied wrenches.

Whether you need precise low-pressure control, ultra-low swept volume for detector-sensitive applications, or high-pressure regulation for demanding LC workflows, Chrom Tech provides a full range of IDEX Back Pressure Regulators and accessories—many stocked and ready to ship.

Back Pressure Assemblies

Part No Pressure Setting Holder Material Includes Swept Volume
P-7905 PSIPEEK(2) XP-215134 µL
P-79120 PSIPEEK(2) XP-215134 µL
P-78540 PSIPEEK(1) P-761, (2) XP-215131 µL
P-78675 PSIPEEK(1) P-762, (2) XP-215131 µL
P-787100 PSIPEEK(1) P-763, (2) XP-215131 µL
P-788250 PSIPEEK(1) P-764, (2) XP-235102 µL
P-789500 PSIPEEK(1) P-765, (2) P-250, (2) LT-11596 µL
P-4551,000 PSIPEEK(1) P-796, (2) P-250, (2) LT-11589 µL
U-60540 PSISST(1) P-761, (2) XP-201129 µL
U-60675 PSISST(1) P-762, (2) XP-201129 µL
U-607100 PSISST(1) P-763, (2) XP-201129 µL
U-608250 PSISST(1) P-764, (2) XP-20199 µL
U-609500 PSISST(1) P-765, (2) XP-20193 µL
U-610750 PSISST(1) P-795, (2) P-250, (2) LT-11591 µL
HIGH PRESSURE ADJUSTABLE BPR ASSEMBLY
P-8802,000–5,000 PSI—(2) F-120BLK9 µL

Replacement Cartridges

Part No Pressure Setting Body Endcap Swept Volume
P-76140 PSITanBlue125 µL
P-76275 PSITanYellow125 µL
P-763100 PSITanRed125 µL
P-764250 PSITanWhite95 µL
P-765500 PSITanGreen89 µL
P-795750 PSIBlackBlue87 µL
P-7961,000 PSIBlackGreen83 µL

BPR Holders

Part No Holder Style Holder Material Includes Swept Volume
P-465 Biocompatible BPR PEEK (2) P-250, (2) LT-115 7 µL
U-469 High Pressure BPR SST (2) F-300 4 µL

Ultra-Low Volume BPR

Part No Description Pressure Setting Tubing OD Swept Volume Includes
M-410 Low Flow 100 PSI (7 bar) 1/16" 6 µL XP-230
M-412 Low Flow 500 PSI (34 bar) 1/16" 6 µL XP-230
M-420 High Flow 100 PSI (7 bar) 1/16" 6 µL XP-230
Key Definitions â–¸
Back Pressure Regulator (BPR)
A precision device used to maintain consistent downstream pressure in fluidic systems, helping prevent outgassing and improving pump check valve efficiency in HPLC, UHPLC, and LC-MS workflows.
Swept Volume
The internal volume added to the fluid path by a regulator or fitting. Ultra-low volume BPRs minimize dispersion, with swept volumes as low as 6 ÂµL for multi-detector and low-dead-volume applications.
BPR Cartridge
A replaceable, factory-preset pressure element manufactured from materials such as PEEK, ETFE, perfluoroelastomer, or gold-plated stainless steel. Cartridges generate fixed back pressures (typically 40–1,000 psi) and install into standard BPR holders.
BPR Assembly
A complete regulator unit consisting of a holder and factory-installed cartridge. Assemblies are available in biocompatible PEEK or 316 stainless steel configurations and are designed to deliver incremental back pressures from 5 to 1,000 psi (0.3–69 bar).
Operating Flow Range
The recommended flow rate window for stable pressure regulation—typically 0.1 to 10 mL/min for IDEX BPR cartridges. Within this range, back pressure generally remains within ±10% of the rated value.
Installation Torque
The tightening force required for proper cartridge performance—approximately 20 in-lbs. This is achieved by finger tightening the holder followed by an additional 1/8–1/4 turn using the supplied wrenches.
Frequently Asked Questions â–¸
Why do I need a back pressure regulator in my LC system?
Back pressure regulators help maintain consistent downstream pressure, which reduces solvent outgassing, improves pump check valve performance, and stabilizes detector baselines. They are especially useful in low-pressure or multi-detector LC configurations.
Where should a back pressure regulator be installed?
BPRs are typically installed downstream of the detector or at the end of the analytical flow path. This placement maintains positive system pressure while minimizing added dispersion upstream of the column.
What is the difference between a BPR assembly and a cartridge?
A BPR assembly is a complete unit that includes a holder and a factory-installed cartridge. Replacement cartridges are pressure-setting elements that install into compatible holders, allowing users to change back pressure without replacing the entire assembly.
Are IDEX BPR cartridges affected by flow rate?
Within the recommended operating range of approximately 0.1–10 mL/min, IDEX BPR cartridges typically maintain pressure within ±10% of their rated value. Operating outside this range may result in larger pressure variations.
How tight should I install a BPR cartridge?
Cartridges are designed to reach their specified pressure when tightened to approximately 20 in-lbs. This can be achieved by finger tightening the holder and then applying an additional 1/8–1/4 turn with the supplied wrenches.