Buy inline pressure regulators CartReg online

CartReg Inline Pressure Regulators – Precise Pressure Control for Industrial Gas and Fluid Networks

CartReg Inline Pressure Regulators are compact control valves designed for direct integration into pipelines to maintain constant pressure downstream of the regulator. Typical applications include pneumatic control circuits, small to medium-power hydraulic supplies, laboratory systems, process gas networks, and supply lines in manufacturing machinery. CartReg models are characterized by fast response times, low leakage rates, and a clear pressure-to-flow characteristic curve. This saves space compared to external control stations and simplifies installation in confined spaces.

Construction and Materials

CartReg inline regulators typically consist of a housing made of stainless steel (AISI 316 / 1.4404) or high-strength aluminum with a corrosion-resistant coating. Materials are selected according to the medium and operating environment: stainless steel for aggressive gases and humid environments, aluminum for compressed air and neutral media, brass as a cost-effective solution for non-corrosive liquids. Sealing elements include PTFE, NBR, or FKM seals. PTFE is suitable for high chemical resistance and temperatures up to ~200 °C, NBR for standard compressed air and oil, FKM for higher temperatures and chlorine-containing media. The control diaphragm can be made of stainless steel or elastomer-coated fabric, depending on the desired fatigue strength and sensitivity. Valve seats are often hard-coated (e.g., STELLITE) for wear resistance.

Series and Designs

CartReg inline regulators are available in several designs: direct diaphragm regulators for low to medium flow rates, pre-stressed pilot regulators for higher accuracy and high flow rates, and electronically monitorable variants with pressure sensors and actuators. Direct regulators are particularly compact and do not require external control air. Pilot-operated versions achieve tighter control accuracies and higher flow rates, making them suitable for industrial manufacturing plants and process lines.

Connections, Mounting Position, and Installation

Connection options include threaded connections according to ISO 228/1 (G), NPT for export-oriented systems, flange connections according to DIN EN 1092 for direct pipeline mounting, and compression fittings for plastic or copper pipes. Inline regulators are available in straight-through and angle designs. During installation, the permissible mounting position must be observed; many CartReg models operate independently of position thanks to internally mounted diaphragm guides, while high-precision variants require a defined mounting position to minimize friction and hysteresis. Before installation, lines should be flushed and equipped with shut-off valves so that maintenance and replacement work can be carried out without pressure interruption.

Technical Specifications and Selection Criteria

Important specifications include the set pressure range, maximum inlet pressure differential (Δp), leakage rate, response time, flow characteristic curve (Cv or kv value), and permissible medium temperature. The selection of the appropriate CartReg is based on upstream and downstream pressure, volumetric flow, permissible pressure loss in the system, and material compatibility with the medium. Lifespan data in cycles and the interchangeability of seal kits are also crucial for purchase decisions. For safety-relevant applications, compliance with relevant standards (e.g., ATEX for explosive atmospheres, PED for pressure equipment) must be checked.

• Key selection criteria: medium, upstream/downstream pressure, volumetric flow (m3/h), flow coefficient (kv), connection type, temperature range, sealing material, control accuracy, certifications

Operating Behavior and Control Characteristics

CartReg inline pressure regulators ensure constant downstream pressure through mechanical or pilot-operated control. Mechanical regulators use a spring-diaphragm arrangement; the spring force is preset to the target value. Pilot-operated versions use a small auxiliary valve that controls the diaphragm more precisely, thus providing stable downstream pressure even with strongly fluctuating inlet pressure or high flow. For applications with changing loads, pilot-operated CartRegs are the better choice, while direct diaphragm regulators are simpler and more cost-effective for uniform volumetric flow. Characteristic features include low hysteresis, defined settling behavior, and low overshoot, provided that the control resources are correctly dimensioned.

Maintenance, Replacement, and Spare Parts

CartRegs are designed for easy maintenance: replaceable seal kits, easily accessible diaphragms, and modular pilot units enable quick repairs. For low-maintenance processes, it is recommended to choose seals made of PTFE or FKM in conjunction with stainless steel internal parts. Regular inspection intervals depend on operating hours and medium; in abrasive or contaminated lines, more frequent inspection and cleaning are required. When reassembling after maintenance, ensure correct tightening torque of the screw connections and use a medium-appropriate mounting paste to avoid diaphragm distortion and leaks.

Application Examples – Structured Practical Cases

Example 1 – Pneumatic Manufacturing Station: In an assembly cell, a CartReg is installed inline in the compressed air supply to keep the holding and operating air pressure for cylinders constant at 6 bar. The result is reproducible tool behavior and reduced reject rates, as closing and opening forces remain stable.

Example 2 – Laboratory Analytics with Process Gases: A pilot-operated CartReg regulates nitrogen for chromatographic separation. PTFE seals and a stainless steel housing prevent contamination and ensure measurement accuracy. The regulator is located inline between the gas cylinder reducer and the measuring column, ensuring constant flow rates with changing gas supplies.

Example 3 – Coolant Supply for a Machine Tool: A CartReg with a brass housing and NBR seals controls the feed pump so that the pressure at the spray head remains constant. This reduces pressure surges when the pump starts/stops and extends the service life of nozzles and hoses.

Further specific application cases and industry-specific examples can be found on our technology page and in the collection of practical application examples: https://maku-industrie.de/technik and https://maku-industrie.de/anwendungsbeispiele.

Installation Tips and Commissioning

Before commissioning, lines must be vented and checked for foreign bodies. A coarse filter or strainer upstream of the regulator extends the service life of the seals and seats. Adjustment is carried out step by step: reduce upstream pressure, slowly approach the setpoint, and measure at the measuring point downstream of the regulator. For pilot-operated versions, pilot line length and cross-section are relevant; short, direct lines prevent delays and oscillations. After adjustment, system tightness and control stability under load must be verified.

Error Patterns and Quick Solutions

Common malfunctions include an increase in downstream pressure despite constant setting (clogged outlet or seat wear), pressure drop under load (insufficient Kv value), and oscillations (insufficient damping or excessively long pilot lines). Leaks can often be remedied by replacing the seal kit. In case of wear on the valve seat, a refurbishment kit or a complete replacement of the control cartridge should be considered. For safety-critical applications, the implementation of a redundant pressure monitoring system is recommended.

Standards, Certifications, and Safety

CartReg inline regulators should either be PED-compliant or have ATEX certificates for Ex zones, depending on the application. For food or pharmaceutical applications, FDA-compliant seals and surface roughness according to EHEDG/VDMA are relevant. Compliance with these requirements reduces the risk of technical and regulatory problems during operation.

Procurement and Consulting

For correct selection, precise information on upstream and downstream pressure, volumetric flow, medium, temperature range, and installation conditions is necessary. We recommend providing actual field measurement data or standard load profiles. Technical details and further information on materials, connections, and application examples are available on our technology page: https://maku-industrie.de/technik.

FAQs

1. Which seal should I choose for aggressive media?
For aggressive or oxidizing media, PTFE is the first choice due to its chemical resistance and temperature tolerance. FKM is recommended for high temperatures and organic solvents, NBR for standard applications with compressed air or mineral oils.

2. When is a pilot-operated CartReg necessary?
A pilot-operated regulator is advisable for strong fluctuations in inlet pressure, high flow requirements, or when very tight control accuracy is needed. For constant, low to medium volumetric flows, a direct diaphragm regulator is often sufficient.

3. How do I avoid oscillations after installation?
Shorter pilot lines, adequate damping (bypass/throttle options), and correct dimensioning of the Kv value reduce oscillations. Additionally, an upstream filter screen helps to exclude particles in the pilot or main line.