Forsheda Ab

Schlumberger Technology Corporation

Gunnar Parmann

Simon Hastings Bittleston

Bror Gustafsson

Jan-Age Langeland

Nils Lunde

Stefan Petersson

A seismic streamer comprises a substantially solid core having many of the main components of the streamer, namely hydrophones, electronics modules for digitising the outputs of the hydrophones, the main optical and electrical conductor bundles and Keviar strength members, embedded in it. The core also contains a large number of foam buoyancy elements. An outer skin surrounds the core, defining an annular gap around the core, and this annular gap is filled with open-celled polyurethane foam saturated with kerosene. The capsules containing the hydrophones communicate with the annular gap around the core, so that the kerosene can enter the capsules, each of which contains an open-celled polyurethane foam sheath to cushion the hydrophone. In an alternative construction, made possible by using the buoyancy elements in the core to render the core approximately neutrally buoyant in water, the outer skin and the polyurethane foam are omitted, and the core is used on its own as a solid streamer.

Method of making a marine seismic streamer

In a method for forming an end portion of a plastic pipe wherein the end portion is transferred to softened state and the end portion is provided with an internal groove by axially displacing the pipe end portion in relation to a mould ring which is thereby introduced into the pipe end portion. After the forming of the pipe end portion the mould ring is left in the pipe end portion for forming a sealing ring therein. During the forming operation the pipe end portion is supported on a mandrel. In accordance with the invention the mould ring is displaced into the pipe end portion by displacing the ring along the mandrel while the pipe end portion is in its softened condition supported by the mandrel substantially without being displaced along the mandrel.

Method for forming an end portion of a plastic pipe

An apparatus for forming an end portion of a plastic pipe wherein the end portion is transferred to softened state and the end portion is provided with an internal groove by axially displacing the pipe end portion in relation to a mould ring which is thereby introduced into the pipe end portion. After the forming of the pipe end portion the mould ring is left in the pipe end portion for forming a sealing ring therein. During the forming operation the pipe end portion is supported on a mandrel. In accordance with the invention the mould ring is displaced into the pipe end portion by displacing the ring along the mandrel while the pipe end portion is in its softened condition supported by the mandrel substantially without being displaced along the mandrel.

Apparatus for forming an end portion of a plastic pipe

A mould and sealing ring constitutes a mould element in forming a socket end on a pipe consisting of thermoplastic material and seals the space in a pipe joint between the socket end and the spigot end of a pipe introduced into the socket end. The mould and sealing ring comprises an annular sealing portion consisting of elastically yieldable sealing material and a second substantially annular portion for reinforcing the mould and sealing ring consisting of a material which is rigid in relation to said elastically yieldable material and is connected with the elastically yieldable material at a connection surface. The sealing portion and the reinforcing portion constitute two portions positioned adjacent each other on each side of the connection surface in the axial direction of the ring for dividing the ring into a portion which is inactive from the sealing point of view and is active from the forming and locking point of view and a portion which is active from the sealing point of view is substantially inactive from the forming and locking point of view.

Growing community of inventors

Alvoen, Norway

Gunnar Parmann