WIKA L990.40 Specifications

Diaphragm Seals

Application

Process industry diaphragm seal to combine with Bourdon tube
pressure gauges. Intended for corrosive, contaminated, hot or
viscous pressure media.

Design

Internal 3.5” diaphragm with larger displacement and improved
Sensitivity to lower pressure ranges; requires hydraulic fluid to
transmit pressure to instrument

Process Connection

¼” to 1” NPT-female, others see options

Instrument Connection

Capillary, ¼” or ½” NPT-female
Suitable Pressure Ranges (MWP 1500PSI @250°F)

10” H2O to 1500 PSI

Diaphragm-Type Diaphragm Seal

Large Volume Threaded Diaphragm Seals

Type L990.40

Available Options

See Selection Guide (over)

To determine the effects of temperature and response time in a
specific application, contact the factory for an Application
Questionnaire. The information provided will allow WIKA Technical
Support to accurately model your application parameters using state­of-the-art computer simulation techniques.

ACS L990.40

(ACS 99.03)

Selection Guide - Type L990.40

Type L990.40,1/4X1/4F,SS,SS-0,SS,SS,VI,3.5

Notes

1. Capillary connection is
available with a stainless steel
upper housing only.

2. Bolting material supplied will
match upper housing material,
except stainless steel bolts with
titanium upper housing.

3. Lower housing and gasket are
a process wetted part.

4. Customer to supply flushing
plug.

5. Special material metal
bonded to stainless steel upper
housing.

6. Upper housing must be
titanium.

7. Supplied with high tempera­ture stainless steel bolts.

8. Standard material for stainless
steel and carbon steel wetted
parts is Viton® (400°F max.).
Teflon® is standard for all other
wetted parts (500°F max.). Silver­plated Alloy 718 gasket is used
for high temperature applications
(752°F max.).

9. Maximum working pressure
200 PSI.

Upper Housing Material (See note 2)

CS = Carbon steel, nickel-plated

SS = 316 stainless steel

TI = Titanium

Process Connection

1/4F = 1/4” NPT female
1/2F = 1/2” NPT female
3/4F = 3/4” NPT female

1.0F = 1” NPT female

1/4M = 1/4” NPT male
1/2M = 1/2” NPT male
3/4M = 3/4” NPT male

1.0M = 1” NPT male

Diaphragm Size

3.5 = 3.5" effective diaphragm diameter

4.9 = 4.9" effective diaphragm diameter (See note 9)

Gasket Material (See notes 3 & 8)

VI = Viton

TF = Teflon
AS = Alloy 718, silver-plated (See note 7)

®

®

Diaphragm Material

SS = 316 stainless steel

MO = Monel® 400 (See note 5)
HB = Hastelloy® B-2 (See note 5)
HC = Hastelloy® C-276 (See note 5)
TF = 316 stainless steel, virgin Teflon® lined
PF = 316 stainless steel, Teflon® coated
EC = 316 stainless steel, ECTFE (Halar®) coated
TA = Tantalum (See note 5)
TI = Titanium (See note 6)
NI = Nickel 200 (See note 5)
IN = Inconel® 600 (See note 5)
IC = Incoloy® 825 (See note 5)
SA = 316 stainless steel, gold plated

Bolts

CS = Carbon steel, zinc-plated
SS = Stainless steel
HS = High temperature stainless steel

Flushing Connection (See note 4)

0 = None
1 = 1/8” NPT female
2 = 1/4” NPT female
3 = 2x1/8” NPT female
4 = 2x1/4” NPT female

Lower Housing Material (See note 3)

CS = Carbon steel, nickel-plated

SS = 316 stainless steel

MO = Monel® 400
HB = Hastelloy® B-2
HC = Hastelloy® C-276
TI = Titanium
NI = Nickel 200
IN = Inconel® 600
IC = Incoloy® 825

Options not listed may be available,
please consult factory!
Fill Fluid & Mounting options: Please
reference data sheet ACS 99.MO.

Instrument Connection

1/4 = 1/4” NPT female
1/2 = 1/2” NPT female

CPL = Capillary connection (To weld capillary directly to seal, see note 1)

Diaphragm Seal Design (MWP = 1500 PSI)

Type L990.40 = Threaded Process Connection, Large Diaphragm

THE MEASURE OF

Total Performance

Ordering Information:

State computer part number (if available) / type number / size /
range / connection size and location / options required.

Specifications given in this price list represent the state of engineering at the time of printing.
Modifications may take place and the specified materials may change without prior notice

05/01

TM

WIKA Instrument Corporation

1000 Wiegand Boulevard
Lawrenceville, Georgia 30043-5868
Tel: [phone] Fax: [phone]
http://www.wika.com e-mail: [e-mail]