MKS Granville-Phillips 203 Series User manual

Series 203
Instruction Manual
Granville-Phillips®Variable Leak Valve
Instruction manual part number 203026
Revision B - November 2016

Series 203
Instruction Manual
Granville-Phillips®Variable Leak Valve
© 2016 MKS Instruments, Inc. All rights reserved.
Granville-Phillips®is a registered trademark, and mksinstTM is a trademark of MKS
Instruments, Inc. All other trademarks and registered trademarks are the properties of
their respective owners.
Customer Service / Technical Support:
MKS Pressure and Vacuum Measurement Solutions
MKS Instruments, Inc., Granville-Phillips®Division
6450 Dry Creek Parkway
Longmont, Colorado 80503 USA
Tel: [phone]
Fax: [phone]
Email: [email protected]
MKS Corporate Headquarters
MKS Instruments, Inc.
2 Tech Drive, Suite 201
Andover, MA 01810 USA
Tel: [phone]
Fax: [phone]
Email: [email protected]

Series 203 Variable Leak Valve Installation and Operating Instructions i
Contents
1 Safety Hazards . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
2 Important Precautions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
3 Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
3.1 Conductance . . . . . . . . . . . . . . . . . . . . . . . 3
3.2 Throughput . . . . . . . . . . . . . . . . . . . . . . . . . 3
3.3 Maximum Inlet Pressures . . . . . . . . . . . . . . 3
3.4 Gases Controlled . . . . . . . . . . . . . . . . . . . . 3
3.5 Materials . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
3.6 Temperature . . . . . . . . . . . . . . . . . . . . . . . . 4
3.7 Vacuum Connections . . . . . . . . . . . . . . . . . 4
4 Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
5 Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
6 Removing the Driver . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
7 Bakeout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
8 Attaching the Driver . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
9 Packaging for Shipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
10 Troubleshooting
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
11 Certification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
12 Limited Warranty . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
13 Specifications
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

ii Series 203 Variable Leak Valve Installation and Operating Instructions

Series 203 Variable Leak Valve Installation and Operating Instructions 1
Series 203 Variable Leak Installation
and Operating Instructions
1SafetyHazards
2 Important Precautions The Variable Leak is a carefully designed and manufactured variable
conductance device. With proper care and use it will give long and trouble
free service under the most extreme conditions. The following are important
precautions which must be observed at all times to prevent possible
irreparable damage or poor performance.
2.1 DO NOT remove the valve from its container until these instructions
have been read completely.
2.2 Always cover the ports with plastic cap plugs or rubber stoppers and
place the entire unit in a clean polyethylene bag whenever the Leak is
stored, shipped or not connected to the vacuum system. Do not use
cork stoppers or adhesive tape.
2.3 Carefully exclude dust, dirt, chips, moisture and other contaminants. A
liquid seal, formed from condensed vapors on the sealing surface, will
result in loss of leak control. Foreign or corrosive material will
permanently damage the sealing surfaces.
WARNING
Use of certain corrosive gases can cause gases to leak
through the sealed valve or into the atmosphere,
resulting in serious personal injury.
Before using a gas with the valve, check the gas for
compatibility with the following materials:
•Finesilver
• Type 304S ST
WARNING
Exceeding the maximum internal pressure specified
below can cause an explosion, resulting in property
damage or serious personal injury.
• Inlet pressure should never exceed 200 psig.
• For inlet pressures less than one atmosphere, connect the gas
source to either port.
• For gas pressures greater than one atmosphere, connect the gas
source to the center port.

Important Precautions
2Series 203 Variable Leak Valve Installation and Operating Instructions
2.4 Due to the closing torques required, use care when it is necessary to
support the valve by the ports only.
2.5 High temperature bake the Leak valve body only when the Driver
Assembly is removed and the Leak held open with a bake-out clamp.
2.6 Stable ambient temperature is necessary to maintain conductance at
any specific setting.
2.7 Do not increase the counter reading beyond 270 or decrease below the
number at which the Leak seals mass spectrometer leak tight.
Variable Leak Valve Dimensions
Dimensions in mm
(in.)

Description
Series 203 Variable Leak Valve Installation and Operating Instructions 3
3 Description The Variable Leak consists of the Leak Valve, Driver Assembly and the
Mounting Bracket. The Leak Valve has a precisely machined 304 SS
nosepiece welded in the center of a thin 304 SS diaphragm. The diaphragm
is welded to the 304 SS body. The nosepiece seats on a carefully
proportioned pure silver gasket in the valve body.
The removable Driver Assembly actuates the nosepiece, changing the
effective aperture and thus changing the conductance. A high-ratio worm
and gear make it possible to accurately set any conductance value within
the operating range. The counter attached to the driver provides a
convenient method of reproducing approximate leak rates.
3.1 Conductance The conductance of the Variable Leak is continuously variable from 400 cc
per second to 10-10 cc per second. When sealed, the leakage conductance
with one atmosphere across the seal is less than 10-10 standard cc per
second. All metal-to-metal seals suffer from hysteresis, especially at very
low flow rate. Hence, at low flow rates the conductance will, in general, be
higher at a given counter reading when the leak is being opened than at the
same counter reading when the leak is being closed.
If the leak is sealed after use at high flow rates, some gas will continue to
emerge from the seal for several minutes, even though the seal is mass
spectrometer leak tight. This is a normal condition with metal-to-metal
seals.
3.2 Throughput The maximum throughput is 400 standard cc per second with atmospheric
pressure on the inlet. Larger throughputs are attained with higher inlet
pressures. Much lower throughputs may be achieved by reducing the inlet
pressure. Low inlet pressures are advantageous where very low flow rates
are required.
3.3 Maximum Inlet Pressures The maximum inlet pressure depends on how the valve is connected to the
system. For inlet pressures less than one atmosphere either port may be
connected to the gas source. For gas pressures greater than one atmosphere
the gas source must be connected to the center port, to prevent damage to
the valve diaphragm. Inlet pressure should never exceed 200 psig.
3.4 Gases Controlled All dry gases, non-corrosive to Leak Valve materials, can be controlled.
Moist gases, such as undried atmosphere or gases containing oil or other
condensable gases, are difficult to control because a liquid film forms
quickly on the sealing surfaces. This produces a liquid seal which has only
ON or OFF properties. If this condition occurs, a brief vacuum bakeout is
usually sufficient to restore the control properties of the metal-to-metal seal.
3.5 Materials 304 Stainless Steel and fine silver are the only materials in contact with
vacuum in all Leak Valves. All fabrication is by heliarc welding.

Installation
4Series 203 Variable Leak Valve Installation and Operating Instructions
3.6 Temperature The conductance of the Variable Leak is slightly temperature dependent
and will vary if the ambient temperature varies. Bakeout temperatures up to
450°C may be used, provided the driver is removed and the leak is held
open by the bakeout clamp. Do not bake the leak with the driver attached
to a temperature higher than 70°C.
3.7 Vacuum Connections A wide variety of connections are available to make any Variable Leak
adaptable to existing or new systems. Metal tubulation or flanged
connections may be ordered.
Metal tubulation is of Type 304 Stainless Steel in V4 inch 00 x 0.035 inch
wall. The Stainless Steel tubes may be welded to any other 300 Series
except the free machining grades.
Rotatable flanges made of Type 304 Stainless Steel, heliarc welded to Type
304 tubulation, are available. Both the 2¾ inch CuSeal®and 115/16 inch
Mini-CuSeal®flanges are manufactured to geometries licensed by Varian
Associates, Inc. Each of the Flange styles use a different replaceable OFHC
copper gasket between two mating flanges, and type 18-8 bolts, nuts, and
washers, Also available are versions using Cajon®VCR and VCA fittings.
4 Installation Use every precaution to prevent contamination from entering the Leak.
Keep plastic caps or rubber stoppers on the valve ports until the valve is
ready to be connected to the system. Do not use cork or adhesive tape.
When the unit is not installed, the valve should be left slightly open and
placed in a clean polyethylene bag as protection against contamination.
For inlet pressures less than one atmosphere either port may be connected
to the gas source. For pressures greater than one atmosphere the gas source
must be connected to the center port, Port S, to prevent damage to the valve
diaphragm.
All welding operations must be done with an inert atmosphere inside the
valve to prevent the formation of oxide contamination which could enter
the valve and cause failure. Heliarc welding with better than 99% pure
argon inside and a 3 to 4 minute purge is satisfactory.
When flange connections are supplied on the Leak Valve, mating flanges of
the same diameter and style must be provided on the system. Each design
uses a specific OFHC copper gasket. Insert a new, clean gasket between
mating flanges using care not to mar the gasket surfaces. Uniformly tighten
Type 18-8 bolts and nuts with washers until the outer flange surfaces are in
contact. Intimate contact is important for good mechanical strength.

Operation
Series 203 Variable Leak Valve Installation and Operating Instructions 5
5Operation Leak rate is increased as the counter reading is increased. Twenty-seven
turns of the driver handle, or 270 counter numbers above the sealed
position reference number, changes the Leak from full closed mass
spectrometer leak tight to full open. Never increase the counter reading
more than 270 numbers or decrease below the number at which the Leak
seals. Exceeding these limits will not change the conductance but may
shorten Leak Valve life.
The counter has been preset so that the Leak Valve is sealed mass
spectrometer leak tight at a counter reading of about 0010. The counter may
be removed and reset to establish the reference for the fully closed position
at any value desired. It is also possible that the reference may change
inadvertently when the driver is removed. However, the sealed position can
readily be re-determined with a leak detector, and a new reference
established. Damage to sealing surfaces is prevented by a preset clutch.
6 Removing the Driver The driver must be removed for bakeout.
6.1 Remove the name plate.
6.2 Turn the driver handle until the counter reads approximately 150 digits
above the previous sealing point to relieve all thrust on the nosepiece.
6.3 Remove the 6-32 x 1 5/8" retracting screw from the center of the worm
gear.
6.4 Support the Driver Assembly and remove the four symmetrically
placed 8-32 x 1" driver mounting screws and washers located on the
tubulation side of the Leak Valve.
6.5 Place Driver Assembly in a clean polyethylene bag.
6.6 Attach the bakeout clamp to the nosepiece of the Leak Valve and
retract the nosepiece until it contacts the bakeout clamp.
6.7 The Leak Valve is now ready for bakeout.
7 Bakeout High temperature bakeout of a system will greatly decrease the required
pump-down time for pressures below 1 x 10–6 Torr (1.33 x 10–6 mbar,
1.33 x 10–4 Pa). Leak Valves are designed to withstand repeated bakeout to
450 ° C if the driver is removed and the valve is held open with the bakeout
clamp.
Do not subject the valve to high temperatures any longer than necessary.
Excessive baking will shorten the useful life of the valve. Bakeout should
only be done when the pressure on the interior of the valve is below
1x10
–4 Torr (1.33 x 10–4 mbar, 1.33 x 10–2 Pa) so that oxidation is kept to
a minimum.

Attaching the Driver
6Series 203 Variable Leak Valve Installation and Operating Instructions
8 Attaching the Driver When the Leak Valve is cool to the touch, the Driver Assembly may be
attached.
8.1 Remove the bake-out clamp.
8.2 Be certain the counter reads approximately 150 digits above the
previous sealing point and the retracting screw is removed so that the
valve seal cannot be damaged when the driver mounting screws are
tightened.
8.3 Support the Driver Assembly, replace the four 8-32 x 1" driver
mounting screws and washers, and tighten evenly. A small amount of
lubricant should be used on the mounting screws.
8.4 Replace the 6-32 x 1 5/8" retracting screw and tighten until the
shoulder of the screw bottoms on the nosepiece. Do not lubricate this
screw. Compounds which contain sulfur should never contact the
Monel®or nickel valve parts.
8.5 Turn the driver handle clockwise until a mass spectrometer leak tight
seal is attained. This will require between 30 and 50 inch-ounces
torque. If a leak detector is not available, close the valve in small
increments until a satisfactorily low conductance is attained.
8.6 With the driver in the sealed position, remove the counter and set to
read 0010. A properly adjusted clutch will now slip at counter reading
0000.
8.7 To adjust the clutch, remove the driver handle and tighten or loosen
the set screw until the clutch slips about 10 counter numbers below the
sealed position.
8.8 To open the Leak Valve, turn the operating handle counter clockwise.
9 Packaging for Shipment It is necessary to protect the valve against contamination when returning it
for service. Plastic caps or rubber stoppers should be installed on the valve
ports and the entire assembly should be placed in a clean polyethylene bag
as protection against contamination.
10 Troubleshooting The Variable Leak provides long trouble free service if properly used and
cared for. If difficulties are experienced in operating the Leak Valve, the
following information will be useful. For additional assistance, contact the
Granville-Phillips Technical Service Department at 1–303–652–4400 or
email at [email protected].

Troubleshooting
Series 203 Variable Leak Valve Installation and Operating Instructions 7
Symptoms, Causes, and Remedies
Symptom Cause Remedy
Leak has only on or off
properties. Does not give
smooth continuous control.
A liquid film on the sealing
surfaces produced by
allowing moist or vapor
laden gases to flow through
the Leak.
A brief vacuum bakeout at 200 to 300 ° C for a few hours.
Leak will not seal. Insufficient thrust, clutch
slips before seal is attained. Remove the driver handle and tighten the clutch set screw.
After the Leak is sealed, adjust the clutch to slip about 10
counter numbers below the sealed position.
Insufficient thrust, driver
dirty. Remove the driver. Remove the clutch. Remove the
retaining rings holding the drive shaft bearings in place.
Remove the bearings and the worm shaft. The drive screw
worm gear assembly should now be carefully unscrewed.
Clean the drive screw threads with a solvent such as
chlorothene. Do not allow the drive screw worm gear
assembly to come in contact with heat. Clean the worm. Do
not clean the bearings. Relubricate the
contact surfaces of the worm and gear and drive screw with
molybdenum disulfide. Reassemble. Remove the retracting
screw. Loosen the set screw in the aluminum bushing and
rotate one-eighth turn. Tighten set screw and replace the
retracting screw. Test the valve for control. Repeat as
necessary until smooth action is obtained.
Sealing surfaces
contaminated.
Replace Leak Valve body. Glass particles, lint, metal chips
and dust cannot usually be removed.
Leak momentarily opens or
closes in reverse reaction to
the turning of the driver
handle.
Misalignment of Driver
Assembly and Leak Valve. Re-attach the Driver and Leak Valve, tighten the mounting
screws evenly.
Driver Assembly parts out of
alignment.
Remove the retracting screw. Loosen the set screw in the
aluminum bushing and rotate one-eighth turn. Tighten set
screw and replace the retracting screw. Test the valve for
control. Repeat as necessary until smooth action is obtained.
Body mounting screws stick
after bakeout.
Lubrication has evaporated. Place drops of penetrating oil on each screw and let soak for
10 minutes.
Retracting screw strips out
of nosepiece.
Retracting screw not
properly seated.
Always make certain retracting screw is completely engaged
before operating valve.

Certification
8Series 203 Variable Leak Valve Installation and Operating Instructions
11 Certification MKS/Granville-Phillips certifies that this product met its published
specifications at the time of shipment from the factory.
12 Limited Warranty This Granville-Phillips product is warranted against defects in materials and
workmanship for one year from the date of shipment provided the
installation and preventive maintenance procedures specified in this
instruction manual have been followed. Granville-Phillips Company will, at
its option, repair or replace or refund the selling price of an item which
proves to be defective during the warranty period provided the item is
returned to Granville-Phillips Company together with a written statement of
the problem.
13 Specifications
Materials
Seal Pure silver
All other interior surfaces 304 Stainless Steel
Physical Data
Bakeout temperature 450 ° C, bakeout clamp attached
70 ° C valve open or closed driver installed
Seal deformation vs. number of closures Negligible
Increase in closing torque vs. number of
closures Negligible
Flow path, flange to flange, when fully open 168 mm (6.62 in)
Maximum conductance for dry nitrogen at
25 ° C 400 cc/sec.
Leakage conductance when fully closed 10–11 liters/sec.
Normal closing torque 50 inch-ounces
Standard connections Type 304 Stainless Steel, Rotatable CuSeal or
Mini-CuSeal flanges
Maximum Inlet Pressure
Connection type Port A Port B
CuSeal or Mini-CuSeal flange 25 psig 200 psig
Type 304 SS tubulation (welded to system) 25 psig 200 psig

.

Granville-Phillips®Variable Leak Valve
Instruction manual part number 203026
Revision B - November 2016
Series 203
Instruction Manual
Customer Service / Technical Support:
MKS Pressure and Vacuum Measurement Solutions
MKS Instruments, Inc., Granville-Phillips®Division
6450 Dry Creek Parkway
Longmont, Colorado 80503 USA
Tel: [phone]
Fax: [phone]
Email: [email protected]
MKS Corporate Headquarters
MKS Instruments, Inc.
2 Tech Drive, Suite 201
Andover, MA 01810 USA
Tel: [phone]
Fax: [phone]
Email: [email protected]