The filters of the series TNRS are tank-top mounted in-line filters. In addition to the return-line connection they have a suction connection on the clean-side. This suction connection has a preload pressure (fitting pressure) of ≥ 0,5 bar.
This combination, return-line and suction filter, is foreseen for hydraulic circuits which are equiped with minimum 2 feed pumps (2 hydraulic circuits). The preload suction connection is for the full volume flow filtration for the pump with the smaller volume flow.
The operating status in general wherein the preload pressure and the full stream filtration are effecting the QR (return-line flow) > QS (suction flow). When the operating status is QR = QS no preload pressure is effective.
During the operating status QR < QS the suction valve is effective operates at the connection T2, what makes a feeding out of the receptable possible without preload pressure and without filter efficiency.
Return-line filters in the TNRS series are suitable for a working pressure up to 10 bar. Pressure peaks will be absorbed by a sufficient margin of safety.
The filter element according to DIN 24550, T4 consists of a star-shaped, pleated filter material which is supported on the inside by a perforated core tube and is bonded to the end caps with a high-quality adhesive. The flow is from outside to inside. Filter finer than 40 μm should use throw-away elements made of paper or Interpor fleece (glass fibre). Filter elements as fine as 5 μm(c) are available; finer filter elements on request.
INTERNORMEN-Filters can be used for petroleum-based fluids, HW emulsions, water glycols, most synthetic fluids and lubrication fluids. Consult factory for specific fluid applications.
INTERNORMEN-Filters elements are known as stable elements which have excellent filtration capabilities and a high dirt retaining capacity, therefore having a long service life. Due to its practical design, the return-line filter is easy to service.
When changing the filter element a detachable connection between the filter head and the filter bowl prevents a flow back of dirty oil into the tank.

Classified under the Pressure Equipment Directive 97/23/EC for mineral oil (fluid group 2), Article 3, Para. 3.
Classified under ATEX Directive 94/9/EC according to specific application (see questionnaire sheet-no. 34279-4).