MPI Morheat MG1, MG2, MG, MGJ Installation Manual

MPI Morheat Inc

MPI

Installation Manual

MG series - Digital Melt Pressure Gauge

Models: MG1, MG2, MGJ

DIGITAL MELT PRESSURE GAUGE - Installation Guidelines

1. HOLE LOCATION

The best position to mount the gauge is in front of the screw where the polymer is in a good molten state and shear stress is minimized.
For reclaimed extrusion lines, care must be taken that the gauge is situated far enough from hopper to ensure all pellets are melted. Partially
melted pellets can damage the tip.
Gauge Housing should be installed such that it doesn’t get beyond 150F.
Care must be taken if gauge is mounted on the top of extruder. Heat rises and will heat the housing. If you can touch the housing, it is probably
fi ne. If necessary, fl ex armour style may be recommended to get housing away from heat.

2. DRILLING MOUNTING HOLE

Follow outlines in the DRILL KIT MANUAL. Some points to take care.
a. MOUNTED HOLES CONCENTRICITY:
The gauge tip must be mounted in the center of the hole (within 0.002”).
If the tip is not in the center, the gauge tip can be deformed during installation or removal.
This can increase the error, or even cause the tip to fail prematurely.
b. RECESSING OF THE TIP
The gauge tip should be installed within 0.08” to 0.1” of the interior of the extuder barrel. Any further, and this can create
a cavity for polymers to collect, harden and then interfere with the pressure reading.
Some materials (such as nylons and polycarbonates) will actually shrink and pull the diaphragm towards to interior of the extruder. This some-

times causes the diaphragm to be ripped off . These materials should be recessed to approx 0.005”.

MOUNTING HOLE DETAILS

INSTALLATION MANUAL - MG DIGITAL GAUGE

3. GAUGE INSTALLATION

Use a high temp anti seize compound to make it easier to remove gauge.
Mounting torque - 100-200inch/lbs (max 500inch/lbs)

Polymer must be in a molten state when gauge is installed.

WIRING : DIGITAL MELT PRESSURE GAUGE

MPI

GAUGE WIRING

RED
PROCESS VALUE

RETRANS OUTPUT
ADJUSTMENT

Warning : only a trained technician

should adjust

ZERO and ALARM ADJUSTMENT

GREEN
ALARM VALUE

ZERO ADJUST

make sure PSI=0

ALARM ADJUST

Adjust GREEN bar graph to setpoint

INSTALLATION MANUAL - MG DIGITAL GAUGE

MPI

DIGITAL MELT PRESSURE GAUGE - Operational Guidelines

A. AVOID COLD STARTS

If the extruder is not heated up properly, the polymer can be in a solid state by the gauge.
If the extruder is then started, the diaphragm can be ripped off .

B. GAUGE REMOVAL

The gauge should only be removed or replaced while the machine is at operating temperature and the polymer is in a liquid state.
Removal of the gauge from a cold extruder may cause the polymer to adhere to the diaphragm , and pull off or damage the diaphragm. A gauge
should never be installed into a mounting hole where there is solid polymer. If the diaphragm is forced against a solid, the gauge can easily be
overloaded and left with a very high zero off set - too high to be rezeroed by the zero potentiometer on the instrument or even damage the tip
altogether.

ALWAYS CLEAN and CHECK TIP RECESSION before reinserting gauge.

C. TIP CLEANING

If the gauge is removed from the barrel and it is still warm, the tip can be carefully cleaned with a clean soft cloth.

D. HOLE CLEANING

Mounting holes should always be cleaned prior to installation. Any burrs or hardened polymer material may cause the diaphragm to be damaged
during installation.
As the inner extruder barrel wears, it can reduce the size of the gauge hole.
Cleaning kits are available from MPI for 1/2-20UNF and M18x1.5 gauge holes and this will help ensure hole is maintained at the right size..

E. CHECK TIP RECESSION BEFORE REINSERTING

As the extruder barrel wears, the gauge tip will get closer and closer to the inner barrel wall. If it is allowed to be fl ush with the extruder inner bar­rel wall, it will wear at the same rate as the inner wall. MPI recommends maintaining a minimum 0.02” recession. Copper shims can be made to

push the tip away from inner wall.

F. KEEP DIGITAL GAUGES DRY

Do not allow oil or water to come in contact with gauge or cables.

TROUBLESHOOTING

1. INDICATOR FULL SCALE Check continuity of cables

Make sure gauge tip is not bottoming out

2. INDICATOR UNSTABLE READING Check continuity of cables
Check wire connections on indicator is tight
Install away from high HP motors

3. INDICATOR READS ONLY “0” Check tip of gauge for damage.
If still the same after calibration - return to MPI

4. INDICATES WRONG PRESSURE Perform Zero adjustment. - AFTER 30min of warm up time.
If still the same after adjustment - contact factory

5. INDICATES READS “LLLL” Adjust ZERO setpoint (make sure pressure = 0psi)
If stays same - contact factory

6. INDICATES READS “FFFF” Adjust ZERO setpoint (make sure pressure = 0psi)
If stays same - contact factory

INSTALLATION MANUAL - MG DIGITAL GAUGE

GAUGE / TRANSMITTER / RUPTURE DISK - TIP SPACERS

STOCK LIST - TIP SPACER

THICKNESS 1/2”-20 UNF

0.025” (0.64mm) MP-SPACER-025

0.032” (0.81mm) MP-SPACER-032

0.045” (1.14mm) MP-SPACER-045

0.063” (1.60mm) MP-SPACER-063

0.090” (2.29mm) MP-SPACER-090

MOUNTING HOLE DRILL KITS

MODEL THREAD

STOCK LIST - DRILL KITS

MP-DRILL-1/2 1/2”-20 UNF

MP-DRILL-5/8 5/8”-11 UNC

MP-DRILL-M10 M10x1.0

MP-DRILL-M18 M18x1.5

MP-DRILL-M14 M14x1.5

MPI

MPI melt pressure gauges, transducers and transmitter mounting hole drill kits are used to make the highly precise holes
that are required for proper pressure sensor and extruder rupture disk operation. Our drilling kits include tools for tip hole
drilling, 45° seat surface, and thread tapping.

Drilling kits are available for the following threads: ½-20UNF, 5/8-11NC, ¾-16UNF, M18x1.5, and M14x1.5. Custom thread
options are also available.

Please note that the drilling should be performed with zero pressure in the system.

MOUNTING HOLE CLEANING KITS

STOCK LIST - DRILL KITS

MODEL THREAD

MP-CLEAN-1/2 1/2”-20 UNF

MP-CLEAN-5/8 5/8”-11 UNC

MP-CLEAN-3/4 3/4”-16 UNF

MP-CLEAN-M18 M18x1.5

MP-CLEAN-M14 M14x1.5

MPI melt pressure gauge/transducer/transmitter mounting hole cleaning kits are used to clean plastic residue from dirty or
plugged holes before installing pressure sensors or extruder rupture disks. Hardened plastic residue is one of the leading
causes of failures of melt pressure sensors or extruder rupture disks. The hardened plastic residue can damage the fragile
diaphragm on the tip of the pressure sensors and extruder rupture disks, and can make them ineff ective.

Cleaning kits include tools for tip hole cleaning, 45° seat surface, and thread cleaning. Please note that the cleaning should
be performed when the polymer is molten, with zero pressure in the system.

Cleaning kits are available for the following threads: ½-20UNF, 5/8-11NC, ¾-16UNF, M18x1.5, and M14x1.5. Custom thread
options are also available.

MPI Morheat inc.

SALES & SERVICE
21 Meteor Dr., Toronto
Ontario, Canada M9W 1A3

ph [phone] toll free ph [phone]
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