Endress+Hauser CPA842 Unifit Hygienic Process Assembly

CPA842 Unifit fixed-mount hygienic sensor assembly

The Endress+Hauser CPA842 is a Unifit process assembly: a permanently installed, hygienic holder for 12 mm (Pg 13.5) liquid analysis sensors. It is the simpler, fixed counterpart to a retractable assembly. The sensor stays in the process, and the holder protects it and seals it against the vessel or pipe. It is used in food and beverage, life sciences and chemical processing, where the line can be emptied and depressurized for sensor changes. Seven Star LLC, an independent supplier in Muscat, supplies the CPA842 and the sensors and transmitters that go with it in Oman and the GCC.

The order code of the CPA842 has the pattern CPA842-XXXXXX1 followed by option codes. The two letters that identify the process connection (for example AA, AB, AC, OD, AE, AF, AG, AK, AH) are used in the dimension table of the datasheet, and plus-codes add features such as sensor protection (+NB), a protection guard with PAL connection (+NANB) or a protection cover (+NBNC). Leakage detection is part of the 3-A version (+LB) and the EHEDG version (+LC), and can also be ordered separately (+ND).

CPA842 technical specifications

How the CPA842 seals the sensor in a hygienic process

The sensor is screwed into the holder with a flush-mounted, gap-free sealing ring, which avoids the crevices where product and bacteria can remain. The molded process seal and the sensor seal are the only elastomer parts that see the medium. The holder is machined from 1.4435 stainless steel with an electropolished finish, so wear in the wetted area is practically absent and corrosion resistance stays high. Versions in 1.4435 and Alloy C22 can be autoclaved.

Where a seal fails, the leakage detection bore above the process connection shows product escaping from the molded seal before it reaches the outside. This is built into the 3-A and EHEDG versions. Hygienic design follows 3-A, EHEDG and ASME BPE requirements, and the datasheet lists the certificates that can be supplied depending on the version: ASME BPE CoC, FDA 21 CFR, EU food contact regulation 1935/2004, GB 4806, 3-A, EHEDG, CRN, inspection certificate 3.1, surface roughness test and a manufacturer declaration for explosive atmospheres.

CPA842 process connections and immersion depth

The values X0, X1 and X2 are immersion dimensions from the manufacturer drawing; the sensor tip depth in the process depends on them and on the mating nozzle, so check them against the vessel nozzle before ordering. The dairy fitting is EHEDG compliant only with a special seal that is not in the standard scope of delivery.

How the CPA842 differs from the CPA875 retractable assembly

The CPA842 has no moving parts and no rinse chamber. It costs less to maintain mechanically and is simpler to specify, but the sensor cannot be pulled out under process pressure. If calibration or replacement must happen without stopping the line, the CPA875 Cleanfit assembly is the right product. Both take the same 12 mm sensor size, and both appear in measuring systems with a Liquiline transmitter such as the CM44x family, the CM448, the CM442R or the CM42B, and a Memosens cable like the CYK10.

Typical sensors listed by the manufacturer for the CPA842 include the CPS61E pH sensor, the CLS82E conductivity sensor and the COS81E oxygen sensor. The CLS82E should be used only in an assembly without sensor protection so that the measuring signal is not affected.

Selection checklist for a CPA842

• Process connection: pick the code that matches the vessel or pipe nozzle, including a weld socket if one is not there.
• Seal material: EPDM, FKM, FFKM or silicone, remembering that silicone molded seals have a lower pressure rating at high temperature and are not lubricated.
• Surface finish: Ra 0.76 or 0.38 µm according to the hygiene standard.
• Certificates: 3-A, EHEDG, ASME BPE, FDA, 3.1 or declaration for explosive atmospheres, as needed for your quality system.
• Sensor protection: none, guard (+NB), guard with PAL connection, or protective cover; not for the CLS82E.
• Leakage detection: required in 3-A or EHEDG versions, optional otherwise.
• Mounting seal: for most connections the customer supplies the seal between the adapter and the nozzle.

Installing and commissioning the CPA842

Install the assembly only when the vessel is empty and the process is without pressure. Use a hook wrench, DIN 1810 flat face, on G1¼ union nuts, because a pipe wrench will damage them. The pipe inside diameter of the mating part must exceed 28 mm for clamp connections. The scope of delivery includes the assembly, the mounted sensor seal, a mounted process seal for DN25 versions and dust caps for the Pg 13.5 thread.

Fit the sensor with the correct seal, tighten to the sensor instruction, and run a CIP and SIP cycle before first measurement if the plant procedure requires it. Check flow velocity so that cavitation and sensor damage are avoided.

Maintenance and spares for the CPA842

Spare seals and welding sockets are ordered through the CPA842 order structure. The manufacturer lists straight and angled safety welding sockets for DN25 and B. Braun ports, and dummy plugs in 316L with FDA-grade FKM for unused ports. Keep a seal kit for the material you chose and replace the molded seal at planned shutdowns. Watch the leakage bore on 3-A and EHEDG versions during rounds.

CPA842 applications in Oman and the GCC

Hygienic fixed assemblies find use in dairy, juice, bottled water and beverage plants, pharmaceutical and biotech utilities, and chemical process lines across Oman and the GCC. Since steam sterilization and caustic cleaning are routine in these plants, seal selection and cleaning cycle data are the first questions to settle. In hot climates, protect the sensor cable and the Memosens head from direct sun and from hot cleaning water spray.

Information to send with a CPA842 request

• Order code, or process connection and sensor protection needs
• Seal material and surface roughness
• Process temperature, pressure, CIP and SIP conditions
• Sensor model and transmitter
• Certificates required (3-A, EHEDG, FDA, 3.1)
• Welding sockets or dummy plugs needed
• Quantity and delivery location in Oman or the GCC

Documents and quotation

The manufacturer technical information for the CPA842 is attached on this page and includes the dimension and immersion tables mentioned above.

Send the code or the application data for your CPA842 and Seven Star LLC will confirm availability and quote.