WIKA L990.34 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

Upper and lower housing welded with Internal welded diaphragm,
threaded process connection; requires hydraulic fluid to transmit
pressure to instrument

Process Connection

¼” NPT to 1” NPT

Instrument Connection

Capillary, ¼” or ½” NPT-female

Suitable Pressure Ranges

2 ½” Gauge: 100PSI to 9000PSI
4 and 4 ½” Gauge: 400PSI to 9000PSI

Diaphragm-Type Diaphragm Seal

All Welded Diaphragm Threaded Diaphragm Seal

Type L990.34

Available Options (connections, materials, flushing ports, etc.)
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 L990.34

(ACS 99.12)

Selection Guide - L990.34

L990.34,1/4X1/4F-0,SS,SS,SS

Notes

1. Customer to supply
flushing plug.

2. Upper housing, diaphragm and
lower housing must be the same
material.

Items in

bold

stock (subject to prior sales).
For optional items, consult
factory for current lead-time.

are av ail able from

Instrument Connection

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

CPL = Capillary connection (To weld capillary directly to seal)

Diaphragm Seal Design (Pressure rating – 9,000PSI)

L990.34 = All Welded Design

Diaphragm Material

SS = 316 stainless steel

MO = Monel® 400 (See note 2)
HC = Hastelloy® C-276

Lower Housing Material

SS = 316 stainless steel

MO = Monel® 400 (See note 2)
HC = Hastelloy® C-276

Upper Housing Material

SS = 316 stainless steel

MO = Monel® 400 (See note 2)
HC = Hastelloy® C-276

Flushing Connection (See note 1)

0 = None

1 = 1/8” NPT female
2 = 1/4” NPT female

Process Connection

1/4F = 1/4” NPT female
1/2F = 1/2” 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

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

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]