# Diaphragm seal with threaded connection — 990.34

> Diaphragm seal with threaded connection, welded design for aggressive, hot, corrosive, environmentally hazardous or toxic media in oil and gas, chemical, petrochemical and water treatment industries.

- Catalog code: 990_34
- Model: 990.34
- Category: Pressure measurement › Diaphragm seals
- Product page: https://avigan.com.ua/wika/en/products/990_34
- Price: on request
- Supplier: AVIGAN (TOV VIKA Prylad), official WIKA partner in Ukraine

## Overview

Wide selection of materials and fully welded: The threaded connections and 990.34 diaphragm seals are suitable for aggressive, contaminated or hot media.

## Applications

- Aggressive, hot, corrosive, environmentally hazardous or toxic media
- Oil and gas industry, chemical and petrochemical industries
- Water treatment
- Versatile in application

## Special features

- Process connection with thread
- Version with internal diaphragm, diaphragm seal parts fully welded
- Large selection of process connections and materials
- Flushing connections optionally available
- High pressures up to 1,000 bar [14,500 psi] can be achieved

## Specifications

| Parameter | Value |
|---|---|
| model | 990.34 |
| product family | 990 |
| short description | Diaphragm seal with threaded connection, welded design for aggressive, hot, corrosive, environmentally hazardous or toxic media in oil and gas, chemical, petrochemical and water treatment industries. |
| subcategory | Diaphragm seal |
| certifications | EAC; CRN; MTSCHS |
| languages in datasheet | en; de |
| pressure ranges | 0 … 0.6 bar; 0 … 1000 bar; 0 … 8.7 psi; 0 … 14500 psi |
| process connections | 1 NPT; 9/16-18 UNF; 3/4-16 UNF; M20 x 1.5; G1A; G ½ A; G ¼ A; G ⅜ A; G ¾ A; G 1 A; G 1 ½ A; ½ NPT; ¼ NPT; ⅜ NPT; ¾ NPT; 1 ½ NPT; R ½; R ¼; R ⅜; R ¾; G½A; G¼A; G⅜A; G¾A; ½NPT; ¼NPT; ⅜NPT; ¾NPT; 1½NPT; R½; R¼; R⅜; R¾; G1/2A; G1/4A; G3/8A; G3/4A; G11/2A; G1/4; G3/8; G3/4; G1; 1/2NPT; 1/4NPT; 3/8NPT; 3/4NPT; 1NPT; 11/2NPT; 9/16-18UNF; 3/4-16UNF; M20x1.5; R1/2; R1/4; R3/8; R3/4; R1 |
| case material | Stainless steel 1.4404 (316L); Stainless steel 1.4571 (316Ti); Stainless steel 1.4539 (904L); Stainless steel 1.4541 (321); Duplex 2205 (1.4462); Superduplex 2507 (1.4410); Hastelloy C22 (2.4602); Hastelloy C276 (2.4819); Inconel 625 (2.4856); Incoloy 825 (2.4558); Titanium grade 2 (3.7035); Monel 400 (2.4360) |
| wetted parts material | Stainless steel 1.4404 (316L); Stainless steel 1.4571 (316Ti); Stainless steel 1.4539 (904L); Stainless steel 1.4541 (321); Duplex 2205 (1.4462); Superduplex 2507 (1.4410); Hastelloy C22 (2.4602); Hastelloy C276 (2.4819); Inconel 625 (2.4856); Incoloy 825 (2.4558); Titanium grade 2 (3.7035); Monel 400 (2.4360) |
| process temp | -20 … 400 °C |

## Datasheet tables

| Model 990.34 | 2 |
|---|---|
| Pressure range (see pressure-temperature diagrams from page 4) | 0 ... 0.6 bar [0 ... 8.7 psi] to 0 ... 1,000 bar [0 ... 14,500 psi] other units (e.g. psi, kPa) as well as all equivalent vacuum or combined pressure and vacuum ranges are available. |
| Level of cleanliness of wetted parts | ■ Oil and grease free per ASTM G93-03 level FWIKA standard (< 1,000 mg/m 2 ) ■ Oil and grease free per ASTM G93-03 level D and ISO 15001 (< 220 mg/m 2 ) |
| Origin of wetted parts | ■ International ■ EU, CH, USA |
| Connection to the measuring instrument | ■ Axial gauge adapter ■ Axial gauge adapter with female threadG½,G¼,½NPTor¼NPT ■ Male thread 9/16-18 UNF |
| Type of mounting | ■ Direct mounting ■ Capillary ■ Cooling element |
| Flushing connection | ■ Without ■ Single flushing connection (G ¼, G⅛, ¼NPT, ⅛NPT) ■ Dual flushing connection (G ¼, G⅛, ¼NPT, ⅛NPT) ■ Plug screws |
| Design per NACE | ■ Without ■ MR0175 ■ MR0103 |
| Vacuum service (see IN 00.25) | ■ Basic service ■ Premium service ■ Advanced service |
| Instrument mounting bracket (only for versions with capillary) | ■ Without ■ Form H per DIN 16281, 100 mm, aluminium, black ■ Form H per DIN 16281, 100 mm, stainless steel ■ Bracket for pipe mounting, for pipe outer Ø20 ... 80 mm, steel (see data sheet AC 09.07) |

| Standard | Male thread | Female thread |
|---|---|---|
| Following DIN ISO 228-1 | ■ G½A ■ G¼A ■ G⅜A ■ G¾A ■ G1A | ■ G½ ■ G¼ ■ G⅜ ■ G¾ ■ G1 |
| Following ANSI B 1.20.1 | ■ ½NPT ■ ¼NPT ■ ⅜NPT ■ ¾NPT ■ 1 NPT ■ 1½NPT | ■ ½NPT ■ ¼NPT ■ ⅜NPT ■ ¾NPT ■ 1 NPT |
| Following ANSI B 1.1 | ■ 9/16-18 UNF ■ 3/4-16 UNF | ■ 9/16-18 UNF ■ 3/4-16 UNF |
| Following DIN 13-1 | ■ M20 x 1.5 | ■ M20 x 1.5 |
| Following ISO 7-1 | ■ R½ ■ R¼ ■ R⅜ ■ R¾ |  |

| 1 | 2 | 3 | 4 | 5 |
|---|---|---|---|---|
| Material of upper body of diaphragm seal and wetted parts 1) | Nominal pressure (PN) in bar for effective diameter of diaphragm Mb inmm |  |  |  |
|  | PN 160 | PN 400 | PN 600 | PN 1000 |
| Stainless steel 1.4404 (316L) | Mb 52 | Mb 40, Mb 29 | Mb 22 |  |
| Stainless steel 1.4571 (316Ti) | Mb 52 | Mb 40, Mb 29 |  |  |
| Stainless steel 1.4539 (904L) | Mb 52 |  |  |  |
| Stainless steel 1.4541 (321) | Mb 52 |  |  |  |
| Duplex 2205 (1.4462) | Mb 52 | Mb 40 | Mb 29 |  |
| Superduplex 2507 (1.4410) | Mb 52 |  |  |  |
| Hastelloy C22 (2.4602) | Mb 52 |  | Mb 29 |  |
| Hastelloy C276 (2.4819) | Mb 52 | Mb 40, Mb 29 |  | Mb 22 |
| Inconel 625 (2.4856) | Mb 52 | Mb 40 | Mb 29 | Mb 22 |
| Incoloy 825 (2.4558) | Mb 52 | Mb 40, Mb 29 | Mb 22 |  |
| Monel 400 (2.4360) 2) | Mb 40, Mb 29 |  |  |  |
| Titanium grade 2 (3.7035) | Mb 52 | Mb 29 |  |  |

| Logo | Description | Country |
|---|---|---|
|  | EAC (option) Pressure equipment directive | Eurasian Economic Community |
| - | MTSCHS (option) Permission for commissioning | Kazakhstan |
| - | CRN Safety (e.g. electr. safety, overpressure, ...) | Canada |

| 1 | 2 | 3 | 4 | 5 |
|---|---|---|---|---|
| G | Dimensions in mm[in] |  |  |  |
| D | H 1) | h M | SW |  |
| G ¼ A | 64 [2.52] | 54.5 ... 75.5 [2.15 ... 2.93] | 13 [0.51] | 27 [1.06] |
| G 3/8 A | 64 [2.52] | 54.5 ... 75.5 [2.15 ... 2.93] | 16 [0.63] | 27 [1.06] |
| G½A | 64 [2.52] | 54.5 ... 75.5 [2.15 ... 2.93] | 20 [0.79] | 27 [1.06] |
| G¾A | 64 [2.52] | 54.5 ... 75.5 [2.15 ... 2.93] | 20 [0.79] | 41 [1.61] |
| G 1 A | 64 [2.52] | 54.5 ... 75.5 [2.15 ... 2.93] | 28 [1.10] | 41 [1.61] |
| ¼ NPT | 64 [2.52] | 54.5 ... 75.5 [2.15 ... 2.93] | 13 [0.51] | 27 [1.06] |
| ½NPT | 64 [2.52] | 54.5 ... 75.5 [2.15 ... 2.93] | 19 [0.75] | 27 [1.06] |
| ¾NPT | 64 [2.52] | 54.5 ... 75.5 [2.15 ... 2.93] | 20 [0.79] | 32 [1.26] |
| 1 NPT | 64 [2.52] | 54.5 ... 75.5 [2.15 ... 2.93] | 25 [0.98] | 41 [1.61] |
| M20 x 1.5 | 64 [2.52] | 54.5 ... 75.5 [2.15 ... 2.93] | 20 [0.79] | 27 [1.06] |
| R ¼ | 64 [2.52] | 54.5 ... 75.5 [2.15 ... 2.93] | 15 [0.59] | 27 [1.06] |
| R½ | 64 [2.52] | 54.5 ... 75.5 [2.15 ... 2.93] | 19 [0.75] | 27 [1.06] |
| R 1 | 64 [2.52] | 54.5 ... 75.5 [2.15 ... 2.93] | 19 [0.75] | 41 [1.61] |
| 1 ⅛ -12 UNF | 64 [2.52] | 54.5 ... 75.5 [2.15 ... 2.93] | 19 [0.75] | 41 [1.61] |

| 1 | 2 | 3 | 4 | 5 |
|---|---|---|---|---|
| G | Dimensions in mm[in] |  |  |  |
|  | D | H 1) | h F | SW |
| G ¼ | 64 [2.52] | 54.5 ... 75.5 [2.15 ... 2.93] | 13 [0.51] | 27 [1.06] |
| G 3/8 | 64 [2.52] | 54.5 ... 75.5 [2.15 ... 2.93] | 16 [0.63] | 27 [1.06] |
| G½ | 64 [2.52] | 54.5 ... 75.5 [2.15 ... 2.93] | 19 [0.75] | 27 [1.06] |
| G¾ | 64 [2.52] | 62.5 ... 83.5 [2.46 ... 3.29] | 24 [0.94] | 32 [1.26] |
| ¼ NPT | 64 [2.52] | 54.5 ... 75.5 [2.15 ... 2.93] | 13 [0.51] | 27 [1.06] |
| ½NPT | 64 [2.52] | 54.5 ... 75.5 [2.15 ... 2.93] | 19 [0.75] | 27 [1.06] |
| ¾NPT | 64 [2.52] | 54.5 ... 75.5 [2.15 ... 2.93] | 22 [0.87] | 32 [1.26] |
| 1 NPT | 64 [2.52] | 68.5 ... 89.5 [2.70 ... 3.52] | 26 [1.02] | 46 [1.81] |

| 1 | 2 | 3 | 4 |
|---|---|---|---|
| G | Dimensions in mm[in] |  |  |
|  | D | H 1) | h M |
| G ¼ A | 54 [2.13] | 48 ... 66 [1.89 ... 2.60] | 13 [0.51] |
| G 3/8 A | 54 [2.13] | 48 ... 66 [1.89 ... 2.60] | 16 [0.63] |
| G½A | 54 [2.13] | 48 ... 66 [1.89 ... 2.60] | 20 [0.79] |
| G¾A | 54 [2.13] | 48 ... 66 [1.89 ... 2.60] | 20 [0.79] |
| G 1 A | 54 [2.13] | 48 ... 66 [1.89 ... 2.60] | 28 [1.10] |
| ¼ NPT | 54 [2.13] | 48 ... 66 [1.89 ... 2.60] | 13 [0.51] |
| ½NPT | 54 [2.13] | 48 ... 66 [1.89 ... 2.60] | 19 [0.75] |
| ¾NPT | 54 [2.13] | 48 ... 66 [1.89 ... 2.60] | 20 [0.79] |
| 1 NPT | 54 [2.13] | 48 ... 66 [1.89 ... 2.60] | 25 [0.98] |
| M20 x 1.5 | 54 [2.13] | 48 ... 66 [1.89 ... 2.60] | 20 [0.79] |
| R ¼ | 54 [2.13] | 48 ... 66 [1.89 ... 2.60] | 15 [0.59] |
| R½ | 54 [2.13] | 48 ... 66 [1.89 ... 2.60] | 19 [0.75] |

| 1 | 2 | 3 | 4 |
|---|---|---|---|
| G | Dimensions in mm[in] |  |  |
|  | D | H 1) | h F |
| G ¼ | 54 [2.13] | 51 ... 69 [2.01 ... 2.72] | 13 [0.51] |
| G½ | 54 [2.13] | 51 ... 69 [2.01 ... 2.72] | 19 [0.75] |
| ¼ NPT | 54 [2.13] | 51 ... 69 [2.01 ... 2.72] | 13 [0.51] |
| ½NPT | 54 [2.13] | 51 ... 69 [2.01 ... 2.72] | 19 [0.75] |
| 9/16-18 UNF | 54 [2.13] | 53 ... 71 [2.09 ... 2.76] | 11.2 [0.44] |

| 1 | 2 | 3 | 4 |
|---|---|---|---|
| G | Dimensions in mm[in] |  |  |
|  | D | H 1) | h M |
| G ¼ A | 40 [1.57] | 46 ... 65 [1.81 ... 2.56] | 13 [0.51] |
| G½A | 40 [1.57] | 46 ... 65 [1.81 ... 2.56] | 20 [0.79] |
| G 1 A | 40 [1.57] | 46 ... 65 [1.81 ... 2.56] | 28 [1.10] |
| ¼ NPT | 40 [1.57] | 46 ... 65 [1.81 ... 2.56] | 13 [0.51] |
| ½NPT | 40 [1.57] | 46 ... 65 [1.81 ... 2.56] | 19 [0.75] |
| 1 NPT | 40 [1.57] | 46 ... 65 [1.81 ... 2.56] | 25 [0.98] |
| M20 x 1.5 | 40 [1.57] | 46 ... 65 [1.81 ... 2.56] | 20 [0.79] |
| R ¼ | 40 [1.57] | 46 ... 65 [1.81 ... 2.56] | 15 [0.59] |
| R½ | 40 [1.57] | 46 ... 65 [1.81 ... 2.56] | 19 [0.75] |

| 1 | 2 | 3 | 4 |
|---|---|---|---|
| G | Dimensions in mm[in] |  |  |
|  | D | H 1) | h F |
| G ¼ | 40 [1.57] | 46 ... 65 [1.81 ... 2.56] | 13 [0.51] |
| G½ | 40 [1.57] | 51 ... 70 [2.01 ... 2.76] | 19 [0.75] |
| ¼ NPT | 40 [1.57] | 46 ... 65 [1.81 ... 2.56] | 13 [0.51] |
| ½NPT | 40 [1.57] | 46 ... 65 [1.81 ... 2.56] | 19 [0.75] |
| M16 x 1.5 | 40 [1.57] | 51 ... 70 [2.01 ... 2.76] | 12 [0.47] |
| 3/4-16 UNF | 40 [1.57] | 51 ... 70 [2.01 ... 2.76] | 15.7 [0.62] |

| 1 | 2 | 3 | 4 |
|---|---|---|---|
| G | Dimensions in mm[in] |  |  |
|  | D | H 1) | h M |
| G ¼ A | 34 [1.34] | 36 ... 64 [1.42 ... 2.52] | 13 [0.51] |
| G½A | 34 [1.34] | 36 ... 64 [1.42 ... 2.52] | 20 [0.79] |
| G¾A | 34 [1.34] | 36 ... 64 [1.42 ... 2.52] | 20 [0.79] |
| ¼ NPT | 34 [1.34] | 36 ... 64 [1.42 ... 2.52] | 13 [0.51] |
| ½NPT | 34 [1.34] | 36 ... 64 [1.42 ... 2.52] | 19 [0.75] |
| M20 x 1.5 | 34 [1.34] | 36 ... 64 [1.42 ... 2.52] | 20 [0.79] |
| 9/16-18 UNF | 34 [1.34] | 2) | 2) |
| 3/4-16 UNF | 34 [1.34] | 2) | 2) |

| 1 | 2 | 3 | 4 |
|---|---|---|---|
| G | Dimensions in mm[in] |  |  |
|  | D | H 1) | h F |
| G ¼ | 34 [1.34] | 2) | 13 [0.51] |
| G½ | 34 [1.34] | 2) | 19 [0.75] |
| ¼ NPT | 34 [1.34] | 2) | 13 [0.51] |
| ½NPT | 34 [1.34] | 41 ... 69 [1.61 ... 2.72] | 19 [0.75] |
| M16 x 1.5 | 34 [1.34] | 41 ... 69 [1.61 ... 2.72] | 12 [0.47] |
| 9/16-18 UNF | 34 [1.34] | 41 ... 69 [1.61 ... 2.72] | 11.2 [0.44] |
| 3/4-16 UNF | 34 [1.34] | 41 ... 69 [1.61 ... 2.72] | 15.7 [0.62] |

| Material | Unified numbering system (UNS) |
|---|---|
| Stainless steel 316L (1.4404 or 1.4435) | S31603 |
| Stainless steel 904L (1.4539) | N08904 |
| Stainless steel 321 (1.4541) | S32100 |
| Stainless steel 316Ti (1.4571) | S31635 |
| Stainless steel 1.4466 (urea grade) | S31050 |
| Duplex 2205 (1.4462) | S31803 |
| Superduplex 1.4410 | S32750 |
| Tantalum (also lining) | R05200 |
| Hastelloy C276 (2.4819) | N01276 |
| Hastelloy C22 (2.4602) | N06022 |
| Inconel 600 (2.4816) | N06600 |
| Incoloy 825 (2.4858) | N08825 |
| Inconel 625 (2.485) | N06625 |
| Monel 400 (2.4360) | N04400 |
| Nickel 200 (2.4066) | N02200 |
| Nickel 201 (2.4068) | N02201 |
| Titanium 3.7035 (class 2) | R50400 |
| Titanium 3.7235 (class 7) | R52400 |
| Zirconium GR702 | R60702 |

| Designation | Identi- fication number | Solidi- fication point | Boiling/ degradation point | Density at 25 °C | Kin.Viscosity at 25 °C | Remark |
|---|---|---|---|---|---|---|
| KN | °C | °C | g/cm³ | cSt |  |  |
| Silicone oil | 2 | -45 | +300 | 0.96 | 54.5 | Universal application |
| Glycerine | 7 | -35 | +240 | 1.26 | 759.6 | FDA 21 CFR 182.1320 |
| Silicone oil | 17 | -90 | +200 | 0.92 | 4.4 | Low temperatures |
| Halocarbon | 21 | -60 | +175 | 1.89 | 10.6 | Oxygen 1) and chlorine |
| Methylcyclopentane | 30 | -130 | +60 | 0.74 | 0.7 | For very low temperatures |
| High-temperature silicone oil | 32 | -25 | +400 | 1.06 | 47.1 | For high temperatures |
| Neobee® M-20 | 59 | -35 | +260 | 0.92 | 10.0 | FDA 21 CFR 172.856, 21 CFR 174.5 |
| DI water | 64 | +4 | +85 | 1.00 | 0.9 | For ultrapure media |
| Silicone oil | 68 | -75 | +250 | 0.93 | 10.3 |  |
| DI water/propanol mixture | 75 | -30 | +60 | 0.92 | 3.6 | For ultrapure media |
| Medicinal white mineral oil | 92 | -15 | +260 | 0.85 | 45.3 | FDA 21 CFR 172.878, 21 CFR 178.3620(a); USP, EP, SP |

| Maximum temperature | Maximum oxygen pressure |
|---|---|
| to 60 °C | 50 bar |
| > 60 °C to 100 °C | 30 bar |
| > 100 °C to 175 °C | 25 bar |

## Documents

- [ds_ds9904_en_co_458058](https://avigan.com.ua/wika/docs/wika/ds_ds9904_en_co.pdf) — PDF, 880 KB, en
- [ds_in0006_en_co_af8b01](https://avigan.com.ua/wika/docs/wika/ds_in0006_en_co.pdf) — PDF, 1239 KB, en