Access & Retrieval System

The Caproco High Pressure Retrievable system provides access to a process system under full operating conditions. It is capable of operating at pressures up to 6,000 psi (0- 41.4 MPa). This system eliminates the need to interfere with normal operations to obtain vital corrosion data. Key system components are:

1. Access Fitting   2.Solid/Hollow Plug   3. Retriever   4. Service Valve

Basic Principle
Access is gained to the process system by attaching a Caproco Access Fitting. Various connection options (welded, NPT thread, flanged) are available. Once the fitting is attached and a hole is drilled through the pipe/vessel wall using the Caproco drilling machine, a plug is inserted into the fitting to seal the system. Attached to the plug can be a variety of corrosion monitoring equipment, such as: coupon holders, electronic probes or injection equipment. The monitoring device can be removed for servicing or replacement at any time with the use of a Caproco Service Valve and Retriever. To access the monitoring device without process interruption, a service valve and retriever are attached to the access fitting. Once pressure equalization between the line and the service valve/retriever has been achieved, the retriever is used to withdraw the plug and monitoring equipment past the valve, which is then closed to maintain line pressure. The pressure in the retriever is released, allowing it to be removed from the service valve, and the plug and monitoring equipment can be detached to complete the respective servicing.

Access Fittings

Access Fittings can be divided into two categories: Tee and Non-Tee. The more commonly used non-tee style fittings typically hold monitoring equipment such as corrosion coupons and probes.

Sample of Caproco Non-Tee Style Fittings

Standard access fitting bodies are manufactured from hot rolled stock or forged bar; flanged fittings are machined from long weldneck forgings. All Caproco access fittings conform to NACE MR-01-75 Sour Service Specification. Various designs are available to cover a wide variety of monitoring applications.

Access Fitting Process Connection Options:
  • 2" Flare Weld
  • 2" Butt Weld
  • 2" Socket Weld
  • NPT Thread
  • 1"-3" Flanged

Caproco tee style fittings are designed to enable a product to be injected into a system continuously or intermittently. They also enable the operator to draw a fluid sample from the system. The tee on the access fitting (with NPT threaded, socketweld or welded flanged connections) allows a nipple and shut off valve to be attached. Welded side-tee connections are welded using approved procedures and are stress relieved and inspected according to relevant prevailing codes.

Caproco tee access fittings are available in flareweld, buttweld, socketweld, flanged and other styles of line connections, to suit customer requirements.

Sample of Caproco Tee Style Fittings

If desired, tee style access fittings can be used to hold corrosion coupons or probes. The tee on the access fitting body may be sealed off (with a pipe plug or shutoff valve) and the corrosion monitoring equipment mounted on a hollow or solid plug. If a pipe plug is attached to the tee, the tee outlet cannot be used again until the system has been shut down or isolated.

The height of the access fitting body is increased to accommodate the tee. This additional height should be taken into account when calculating the length of the injection / sampling tube or insert.

Standard Caproco access fittings are manufactured to meet most service requirements, however changes in metallurgy will be made on customer request to meet specific service requirements.

Examples of frequently used materials:
  • A350LF2
  • A105N
  • 1020
  • 4130
  • Stainless Steel
  • Duplex TM
  • Incoloy TM
  • Inconel TM

To view the technical catalog sheets on High Pressure Access Fittings,
Non Tee (Click here)
Tee (Click here)
For more information on optional materials / design requirements (Click here)