gefran 85180 - User Manual

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Overview

Function Description
Important Technical Specifications
Usage Features
Maintenance Features

This document is an instruction and maintenance manual for Gefran pressure transducers/transmitters designed for high-temperature applications, specifically in extrusion processes.

Function Description

Gefran M and W series transducers/transmitters are configured for measuring pressure in high-temperature environments. They operate on the principle of hydraulic pressure transmission. Pressure applied to the front (contact) diaphragm is transmitted hydraulically to a sensitive element (strain gauge device) located in a thermally non-critical zone. This design protects the sensitive components from the extreme temperatures of the process. The most delicate part of the transducer is the diaphragm that comes into contact with the measured medium.

Important Technical Specifications

The manual provides detailed mechanical dimensions for the transducers, including various threading types (1/2-20UNF-2A and M18x1.5) and overall lengths. For instance, the rigid rod option "4" has a length of 152.4 mm (6 inches).

Key dimensions for 1/2-20UNF-2A transducers:

D1 (Thread): 1/2-20UNF-2A
D2 (Diameter): Ø 7.8 -0.05 [Ø 0.31" -0.002"]
D3 (Diameter): Ø 10.5 -0.025 [Ø 0.41" -0.001"]
D4 (Diameter): Ø 10.67 [Ø 0.42"]
D5 (Diameter): Ø 12.7 [Ø 0.5"]
A (Length): 5.56 -0.26 [0.22" -0.01"]
B (Length): 11.2 [0.44"]
C (Length): 15.74 [0.62"]
CH (Hex): 16 [5/8"]
E (Length): 152.4 [6"]

Key dimensions for M18x1.5 transducers:

D1 (Thread): M18x1.5
D2 (Diameter): Ø 10 -0.005 [Ø 0.394" -0.002"]
D3 (Diameter): Ø 16 -0.08 [Ø 0.63" -0.003"]
D4 (Diameter): Ø 16 -0.4 [Ø 0.63" -0.016"]
D5 (Diameter): Ø 18 [Ø 0.71"]
A (Length): 6 -0.26 [0.24" -0.01"]
B (Length): 14.8 -0.4 [0.58" -0.016"]
C (Length): 19 [0.75"]
CH (Hex): 19 [3/4"]
E (Length): 152.4 [6"]

For installation, a maximum tightening torque of 56 Nm (500 in-lb) is specified. The closing rods for removal are rated for an applicable pressure of 2000 bar.

Usage Features

The manual outlines several critical aspects for the proper use of these transducers in extrusion applications:

Transducer Installation:

Housing Preparation: The mounting hole must be perfectly prepared using appropriate mechanical tools to ensure correct depth and axiality of holes and tappings. Coaxiality is crucial; diaxialities greater than 0.2 mm can cause transducer breakage during assembly.
Hole Depth: The depth of the holes must prevent the formation of chambers or air pockets where extrusion material could become trapped.
Diaphragm Positioning: The front diaphragm must not extend from the inner wall of the extruder to avoid contact with the extrusion screw or cleaning tools.
Lubrication and Torque: Before installation, the threaded part of the transducer should be lubricated. It must then be installed using a maximum tightening torque of 56 Nm (5 Kgm / 500 in-lb).
Extruder Startup: With the transducer installed and no pressure applied, the system should be brought to its operating temperature. It is essential to wait until all material reaches the same temperature to prevent solid parts from damaging the transducer.

Calibration Procedure:

Temperature Stabilization: The system should be brought to operating temperature with the transducer installed and connected to the measurement instrument, but without any pressure applied.
Zero Reset: Reset the instrument's indication to zero to compensate for temperature-induced zero shift.
Instrument Calibration: Calibrate the instrument to display the calibration value indicated on the transducer data plate (80% of full scale).
Verification: If the instrument does not indicate zero after these steps, repeat the zero reset and instrument calibration. This ensures the instrument is calibrated to provide accurate readings in the chosen engineering unit.

Maintenance Features

Proper maintenance is crucial for extending the life and ensuring the correct functioning of the transducers.

Transducer Care:

Diaphragm Protection: Avoid knocks and abrasions to the contact diaphragm. Always protect the transducer with its cover when removed from its housing.
Cleaning: The transducer should be cleaned with solvents appropriate for the processed material. Any mechanical action on the contact diaphragm can alter its operation and cause damage.
Removal: The transducer should only be removed when the machine is empty (no pressure) but still hot. Solid matter stuck to the contact diaphragm can cause breakage.

Housing Maintenance:

Pre-installation Cleaning: The transducer housing must be cleaned before installation to remove any residues from previous work materials.
Cleaning Tool: A hard metal cutting tool is specifically designed for this purpose.
Cleaning Procedure:
1. Insert the cleaning tool into the housing and screw down the cutting rod (typically 1/4 turn at a time).
2. Turn the pilot cutter clockwise until there is no resistance.
3. Repeat until the housing is completely clean.
Torque Limit for Cleaning: The maximum torque applicable to the pilot cutter is 15 Nm (1.5 Kgm). If higher torque is needed due to blockage, the drilling kit should be used following the recommended procedure.
Cleaning Tool Availability: Cleaning tools are available in versions CT12 (for 1/2-20UNF housing) and CT18 (for M18x1.5 housing).

Tools and Accessories:

Drilling Kits (KF12, KF18): These kits include shaped tools for drilling, reaming, and tapping, facilitating the correct preparation of the assembly housing.
- Drilling Procedure:
  1. Drill the hole with the bit (tool 1).
  2. Ream the hole with the reamer (tool 2).
  3. Drill hole (d4) to a specific depth (tool 3).
  4. Create the sealing seat (tool 4).
  5. Rough-tap the thread (1/2-20UNF-2B or M18x1.5) with the roughing tap (tool 5).
  6. Finish-tap the thread with the finishing tap (tool 6).
Closing Rods (SC12, SC18): These rods are used to verify the dimensions of the assembly housing after preparation and before transducer installation. They are also used for temporary closure when the transducer is removed.
- Verification Procedure:
  1. Coat the rod end with ink.
  2. Lubricate the threaded part.
  3. Insert and screw the rod fully down.
  4. Remove and examine the rod; the ink should be intact on all surfaces except the 45° chamfers.
Mounting Brackets (SF18): Recommended for models with flexible sheathing to precisely fasten the protective housing of the measurement point. The fastening point must be vibration-free and its temperature must not exceed the maximum temperature specified for the strain gauge housing.

Gefran spa reserves the right to make aesthetic and/or functional changes at any time without notice.

gefran 85180 Specifications

General

Brand	gefran
Model	85180
Category	Transducer
Language	English