MTS 286-31 User Manual

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Model 286.31 Transient Permeability Pore Pressure Intensifier

Product Information

015-018-201 C

Trademark information MTS is a registered trademark of MTS Systems Corporation.

Contact information MTS Systems Corporation

14000 Technology Drive Eden Prairie, Minnesota 55344-2290 USA Toll Free Phone: 800-328-2255 (within the U.S. or Canada) Phone: 952-937-4000 (outside the U.S. or Canada) Fax: 952-937-4515 E-mail: info@mts.com http://www.mts.com

Publication information

Manual Part Number Publication Date

015-018-201 B

015-018-201 C

July 1992

August 2007

Contents

Introduction 5

Major Components 6 Control Panel Valves 7 Specifications 9 How the Pressure Intensifier Works 10

The Area Ratio 11

Operation 13

Operating the Control Panel Valves 15 Purging and Filling the Fluid Lines 16

Fill the Fluid Reservoir 17 Purge and Fill the Pressure Intensifier 20 Pressurize the Intensifier 22 Purge and Fill the Lower Pore Line 24 Purge and Fill the Reference Volume 1 Lines 26 Purge and Fill the Balance and Upper Pore Lines 29 Purge and Fill the Reference Volume 2 Lines 32 Purge and Fill the Low Pressure Reservoir Line 35 Purge and Fill the Reservoir Return Line 38 Refill the Pressure Intensifier 41

Running a Steady State Flow Test 44

Fill the Pressure Intensifier 45 Purge and Fill the Pore Pressure Lines 49 Refill the Pressure Intensifier 53 Prepare to Run a Test 56 End the Test 58

Running a Transient Permeability Flow Test 59

Fill the Pressure Intensifier 60 Purge and Fill the Pore Pressure Lines 63 Refill the Pressure Intensifier 67 \Prepare to Run the Test 70 End the Test 77

Maintenance 81

286.31 Transient Permeability Pore Pressure Intensifier

Introduction

This manual documents the Model 286.31 Transient Permeability Pore Pressure Intensifier.

The 286.31 pressurizes fresh, distilled water up to 10,000 psi (69 MPa). The pressurized fluid is applied to a specimen installed in a triaxial cell to test its

permeability characteristics.

286.31 Transient Permeability Pore Pressure Intensifier Introduction

Major Components

vent

is a removable cap that allows air trapped in the system to escape; also the fill point for manually filling the reservoir.

cabinet

fluid reservoir

control panel

identification label

pressure intensifier

actuator manifold

servovalve

houses the 286.31. It has leveling casters and a rear access door. holds the system’s distilled water in a clear acrylic container. has the valves needed to operate the 286.31. Valves are identified by name

and placed in front of a hydraulic schematic of the 286.31 and T riaxial Cell. lists unit specifications such as pressure, reservoir capacity, and fluid type. is an servovalve controlled actuator that operates a pump which boosts pore

pressure fluid up to 10,000 psi (69 MPa). is the connection point for hydraulic components. responds to system control signals to operate the pressure intensifier’s

piston.

reference volumes

Introduction

are two high pressure reservoirs used during transient permeability tests.

286.31 Transient Permeability Pore Pressure Intensifier

Control Panel Valves

286.31 Transient Permeability Pore Pressure Intensifier Introduction

Control Panel Valves

1 Intensifier Fill

2 Reservoir Fill/Drain

3 Reservoir Return

4 Permeability Fluid Input 1

Permeability Fluid Input 2

5 Transducer Input 1 Transducer

Input 2

6 Transducer Pressure Balance

7 Permeability Input Permeability

Output

8 Pore Fluid Input Pore Fluid

Output

controls the flow of fluid from the Reservoir into the Pressure Intensifier.

controls the flow of fluid into the Fluid Reservoir when the 286.31 is connected to a fluid supply.

is normally kept closed.

control the filling and pressurization of Reference Volumes 1 and 2.

apply Reference Volume 1 and 2 pressures to the Pressure Transducer when open.

protect the pressure transducer from damaging high pressures. It is normally left open. When closed it exposes this transducer to the pressure differential between Reference Volumes 1 and 2.

apply Reference Volume 1 and 2 pressures to the specimen in the triaxial cell when open.

bypass the permeability fluid circuit when open.

Introduction

286.31 Transient Permeability Pore Pressure Intensifier

Specifications

Console Dimensions

height width depth

Weight 1000 lb 454 kg

74 in. 24 in. 32 in

1880 mm 610 mm 813 mm

Specifications

Reservoir capacity

Intensifier capacity

Controllable output pressure 12,000 psi

Max. fluid temperature 167°F 75°C

Fluid type distilled water

Hardline fittings F375C (female)

1.6 gal (369 in

0.09 gal (20 in

20,000 psi

) 6.1 litre (6050 cm3)

) 0.34 litre (340 cm3)

80 MPa 140 MPa

286.31 Transient Permeability Pore Pressure Intensifier Introduction

How the Pressure Intensifier Works

FA1P1×=

------=

How the Pressure Intensifier Works

The 286.31’s Pressure Intensifier develops the 10,000 psi (69 MPa) pressures applied to your specimen. The pressure transformer is the part of the Intensifier

that develops this pressure.

The pressure transformer’s principle: low pressure applied to a large area produces a large force. Apply this force over a smaller area and you will produce

a higher pressure.

The hydraulic power supply forces hydraulic fluid into the transformer’s low pressure input side. The resulting force (F) is the product of the supply side’s large piston area (A

HPS (P

) multiplied by the pressure of the hydraulic fluid from the

The force produced (F) transfers to the fluid in the output side. The resulting pressure (P2) is the product of the force (F) divided by the output side’s smaller piston area (A

Introduction

286.31 Transient Permeability Pore Pressure Intensifier

The Area Ratio

area ratio

------=

How the Pressure Intensifier Works

The area ratio is the ratio of the input pressure to the output pressure. It determines how much the input pressure boosts the output pressure. It is

The identification label on your 286.31 gives its area ratio.

For example, your label says the area ratio is 3.33:1. This means a 3000 psi input pressure will produce a 10,000 psi output pressure.

286.31 Transient Permeability Pore Pressure Intensifier Introduction

How the Pressure Intensifier Works

Introduction

286.31 Transient Permeability Pore Pressure Intensifier

Operation

Operation of the 286.31 Intensifier consists of —

• Purging and Filling the Fluid Lines

• Running a Steady State Flow Test

• Running a Transient Permeability Flow Test

Note Complete purging needs only to be done when —

• You first install the 286.31.

• You accidentally draw air into the Pressure Intensifier

Special equipment needed —

• distilled water — at least 2 gallons (8 litres)

• 1% Triton® wetting solution

• Teflon® thread sealing tape

The 286.31 is designed to operate as part of an integrated system that typically includes —

• a Test Controller with closed-loop control electronics

• a hydraulic power supply

• a triaxial cell or pressure vessel installed in a load unit

• a confining fluid pressure intensifier

T o become familiar with your system, make a trial run of the test you want to run. Familiarize yourself with the controls and indicators used in each step, without

actually doing the step.

286.31 Transient Permeability Pore Pressure Intensifier Operation

The following warning, caution, and note apply during all steps.

WARNING

CAUTION

You will be working with very high pressures — The spray from a leak could cut your skin.

The 286.31 develops intensely high pressures (10000 psi/69 MPa). Broken lines or fittings could produce a skin cutting spray.

Stop if you can’t build up to test pressure. You may have a leak somewhere. Reduce pressure to zero, then find and repair the leak.

Fluid hotter than 165°F/75°C can damage the acry lic flui d res erv oi r an d its hoses.

Watch the temperature of the confining fluid in your triaxial cell — especially if your cell has heaters. The confining fluid will heat the pore fluid.

Wait for the confining fluid temperature to cool below 165°F/75°C before drawing the pore fluid back into the 286.31 reservoir.

Use only distilled water in the 286.31— Use any other fluid and you can wreck its seals.

Note Adding a 1% T riton wetting solution to the distilled water will lubricate the

286.31’s seals and make them last longer.

Operation

286.31 Transient Permeability Pore Pressure Intensifier

Operating the Control Panel Valves

Most of the steps in this section involve opening and closing valves on the

286.31’s control panel. The pictures that follow in this section will show you which valves to open and close. The figure below is the key to these pictures.

Operating the Control Panel Valves

A full turn opens a valve completely but still lets you shut it quickly. It takes only light force to shut the valve completely, though using more force won’t hurt it.

286.31 Transient Permeability Pore Pressure Intensifier Operation

Purging and Filling the Fluid Lines

In this section you’ll purge the 286.31’s lines of air and fill them with distilled water.

You only need to do this after installing the 286.31 or if you’ve accidentally drawn air into the Pressure Intensifier through a dry Fluid Reservoir.

Note Before you start purging and filling, make sure your Triaxial Cell is open.

Purging and filling has ten major tasks, which must be done in order

• Fill the Fluid Reservoir

• Purge and Fill the Pressure Intensifier

• Pressurize the Intensifier

• Purge and Fill the Lower Pore Line

• Purge and Fill the Reference 1 Lines

• Purge and Fill the Balance and Upper Pore Lines

• Purge and Fill the Reference 2 Lines

• Purge and Fill the Low Pressure Reservoir Line

• Purge and Fill the Reservoir Return Line

• Refill the Pressure Intensifier

Operation

286.31 Transient Permeability Pore Pressure Intensifier

Fill the Fluid Reservoir

CAUTION

An open Transducer Pressure Balance valve protects the differential pressure transducer from damaging high system pressures —

Keep this valve open except when told to close it.

1. Protect the differential pressure transducer .

Tur n the Transducer Pressure Balance valve to the Open position.

Purging and Filling the Fluid Lines

286.31 Transient Permeability Pore Pressure Intensifier Operation

Purging and Filling the Fluid Lines

2. If there is a specimen installed in the triaxial cell, remove it. Lines cannot be purged and filled with a specimen in place.

You will find instructions for removing the specimen in your Triaxial Cell manual.

3. Prepare to fill the Fluid Reservoir. Turn the Pore Fluid Output, Por e Fluid Input, Permeability Output, and

Permeability Input valves to the Close position.

Operation

286.31 Transient Permeability Pore Pressure Intensifier

Purging and Filling the Fluid Lines

4. Fill the Fluid Reservoir.

If your 286.31 is connected to a distilled water supply —

Tur n the Reservoir Fill/Drain valve to the Open position. When the Fluid Reservoir is about 3/4 full, turn the Reservoir Fill/

Drain valve to the Close position.

If your 286.31 is not connected to a distilled water supply —

Remove the filler plug at the top of the 286.31’s cabinet. Open the console’s rear door . Unscrew one of the hex–head plugs in the

Reservoir. (This allows air to vent more easily out of the Reservoir.) Use a funnel to fill the Fluid Reservoir about 3/4 full.

Seal the filler cap and hex–head plug with Teflon thread sealing tape and reinstall them.

286.31 Transient Permeability Pore Pressure Intensifier Operation

Purging and Filling the Fluid Lines

Purge and Fill the Pressure Intensifier

1. Switch on electrical power at the control console.

2. Set up the test controller to control the 286.31’s Pressure Intensifier from the Manual Control on the RCS (Remote Station Controller).

3. Select the pore pressure control channel’s most sensitive operating range.

4. Select pore pressure as the active control mode.

5. Apply high hydraulic pressure to the 286.31.

Operation

286.31 Transient Permeability Pore Pressure Intensifier

Purging and Filling the Fluid Lines

6. Prepare to purge the Pressure Intensifier of air and fill it with fluid.

Tur n the Permeability Fluid Input 1, Permeability Fluid Input 2, and Reservoir Return valves to the Close position.

Tur n the Intensifier Fill val ve to the Open position.

7. On the test controller, monitor the displacement sensor output.

8. Purge the Pressure Intensifier of air and fill it with fluid.

Slowly turn the Manual Control clockwise, then counterclockwise to fully stroke the Intensifier’s piston.

Watch the displacement signal to make sure you fully stroke the piston. When the bubbling at the Fluid Reservoir stops, use the Set Point or

Manual Control to fully retract the Intensifier’s piston.

286.31 Transient Permeability Pore Pressure Intensifier Operation

Purging and Filling the Fluid Lines

Pressurize the Intensifier

1. On the test controller, monitor the pressure sensor output.

2. Prepare to pressurize the fluid in the 286.31. Tur n the Intensifier Fill val ve to the Close position.

Operation

286.31 Transient Permeability Pore Pressure Intensifier

Purging and Filling the Fluid Lines

3. Extend the Pressure Intensifier’s piston to pressurize the fluid.

On the RSC, slowly turn the Manual Control to develop a slight positive pressure.

While purging, keep the pressure as low as practical but positive all the time. Keep watching the pore pressure as you purge the lines.

If pressure starts dropping and extending the piston does not raise the pressure, you will have to stop and refill the Pressure Intensifier.

Note If the Intensifier needs refilling during this procedure —

1. Shut off any valve that is draining fluid out of the 286.31.

2. Turn the Permeability Fluid Input 1, Permeability Fluid Input 2, and Reservoir Return valves to the Close position.

3. Do the steps in “Refill the Pressure Intensifier” on page 41.

4. Return to the step where you were when the Intensifier ran dry.

5. Turn the Permeability Fluid Input 1, Permeability Fluid Input 2, and Reservoir Return valves back where they were.

286.31 Transient Permeability Pore Pressure Intensifier Operation

Purging and Filling the Fluid Lines

Purge and Fill the Lower Pore Line

1. Purge the lower pore pressure line of air and fill it with fluid.

Tur n the Pore Fluid Input valve to the Open position. Fluid and bubbles will come out of the triaxial cell's lower pore pressure

port. As soon as the bubbles stop, go on to step 2.

Operation

286.31 Transient Permeability Pore Pressure Intensifier

Purging and Filling the Fluid Lines

2. Shut off the flow to the triaxial cell.

Tur n the Pore Fluid Input valve to the Close position.

286.31 Transient Permeability Pore Pressure Intensifier Operation

Purging and Filling the Fluid Lines

Purge and Fill the Reference Volume 1 Lines

1. Prepare to purge the Reference Volume 1 lines of air and fill them with fluid.

Tur n the Permeability Fluid Input 1 valve to the Open position. Tur n the Transducer Input 1 valve to the Close position.

Operation

286.31 Transient Permeability Pore Pressure Intensifier

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