Abstract: A spacer for rotating members mounted on a drive shaft has a substantially tubular body forming a seat for accommodating a drive shaft, the tubular body is made by bending a laminar body, made of rigid material, around a main axis of extension of the seat.

Abstract: An impeller, particularly for centrifugal pumps, including a front plate and a back plate arranged coaxially to a central axis of the impeller and rigidly connected to each other by a plurality of radial blades which are angularly distributed about the central axis; the front plate has a central through opening adapted to connect the impeller to a driving shaft; the impeller includes a reinforcement portion that extends perimetrically to the through opening, at least partially surmounting the front plate; the front plate and the reinforcement portion are constituted by a single part formed by stamping, bending and flattening a metal sheet.

Abstract: A filter for an optical fibre temperature sensor comprising at least one first and one second optical filter for filtering an optical pulse reflected by said optical fibre, characterised in that said at least one first and one second optical filter comprise standard commercial filters complying with ITU specifications, said optical pulse lying within the range from 1570 nm to 1580 nm.

Abstract: A filter for an optical fibre temperature sensor comprising at least one first and one second optical filter for filtering an optical pulse reflected by said optical fibre, characterised in that said at least one first and one second optical filter comprise standard commercial filters complying with ITU specifications, said optical pulse lying within the range from 1570 nm to 1580 nm.