DIMERFLEX ST - Spiral wound gaskets produced by DIMER are particularly suitable for pressure-fluctuating and loaded flange joints in a wide temperature range. They can be applied to pressures up to 250 bar (even more) and they are resistant to high temperatures up to 1100 °C.
They are produced in a variety of basic material combinations with/without an external or an inner metal ring, or in atypical dimensions or shapes according to customer specifications.
Standard sizes according to EN, DIN, ASTM and BS standards, non-standard shapes are also available (ellipse, oval).
On request we can produce DIMERFLEX ST in "soft design" (low stress), using a sealing filler in quality to be used in applications in nuclear power plants, or including internal bars of various shapes according to customer requests / supplied drawings.
In case of leaks and the impossibility to seal up the flange joint using RTJ we can offer a solution by means of the VCS system (ATYP/ASME/ANSI B16.5)
Construction of Spiral wound gasket
1-outer / centering metal ring
2-inner metal ring
3-filler / sealing element / V shaped
4-metal strip / V shaped
4a-outer free metal winding
4b-inner free metal winding
Standard profiles
DIMERFLEX ST10
without outer and inner rings
DIMERFLEX ST20
with inner ring only
DIMERFLEX ST30
with outer ring only
DIMERFLEX ST40
with outer and inner rings
DIMERFLEX ST10Z
with special PTFE sealing zone
Thickness of gaskets
| t1 (mm) | tolerance t1 (mm) | diam.d3 (mm) | bmax (mm) | t2 (mm) | thickness after fitting (mm) |
| 7,2 | +0,35 | 100 - 3200 | 33 | 5,0 | 5,3 - 5,6 |
| 6,4 | +0,3 | 100 - 1600 | 30 | 4,0 | 4,7 - 4,9 |
| 1601 - 3200 | 25 | ||||
| standard 4,5 | +0,3 | 15 - 630 | 35 | 3,0 | 3,2 - 3,4 |
| 631 - 1600 | 30 | ||||
| 1601 - 2000 | 20 | ||||
| 3,5 | +0,25 | 15 - 1000 | 25 | 2,0 | 2,3 - 2,5 |
| 3,2 | 20 | ||||
| 2,5 | +0,25 | 15 - 500 | 10 | 1,5 | 1,8 - 2,0 |
Standard metal materials
| material | AISI / ASTM | spec. acc.to EN 10027-1 | material acc.to EN 10027-2 | BS | ČSN /CZ | temperature (°C) | hardness (HB) | |
| min | max | |||||||
| carbon steel | 238-C | RSt. 37.2 CS | 1.0038 | D/40B | 11 375 | -40 | +500 | 100-120 |
| low carbon steel | - | M2 / ARMCO | 1.1003 | S/LCS | - | -60 | +500 | 90-110 |
| stainless steel | 304 | X5CrNi 18 10 | 1.4301 | 304S 15/16/31 | 17 240 | -250 | +550 | 130-180 |
| stainless steel | 304L | X2CrNi 19 11 | 1.4306 | 304 S11 | 17 249 | -270 | +550 | 130-170 |
| stainless steel | 309 | X15CrNiSi 20 12 | 1.4828 | 309 S24 | 17 251 | -110 | +1000 | 130-220 |
| stainless steel | 316 | X5CrNiMo 17 12 2 | 1.4401 | 316 S31/33 | 17 346 | -200 | +550 | 130-190 |
| stainless steel | 316L | X2CrNiMo 18 14 3 | 1.4404 | 316 S11/13 | 17 349 | -200 | +550 | 120-170 |
| stainless steel | 316Ti | X6CrNiMoTi 17 12 2 | 1.4571 | 320 S31 | 17 348 | -270 | +550 | 130-190 |
| stainless steel | 321 | X6CrNiTi 18 10 | 1.4541 | 321 S12/49/87 | 17 247 | -270 | +550 | 130-190 |
STANDARD FILLERS
| sealing element | temperature (°C) | pH | application | colour coding | |
| min. | max. | ||||
| FG (expanded graphite) | -200 | +550 | 0-14 | aggressive medium | grey |
| PTFE (polytetrafluorethylen) | -200 | +260 | 0-14 | aggressive medium | white |
| CER (ceramic) | -200 | +1100 | - | very high temperature | light green |
| MIC (mica) | -200 | +1000 | - | high temperature | pink |
Table of recommended seating stress
| sealing element | seating stress for DIMERFLEX ST40 (MPa at +20°C) | seating stress for DIMERFLEX ST30 (MPa at+20°C) |
||||
| min. | recommended | max. | min. | recommended | max. | |
| FG (expanded graphite) | 50 | 125 | 300 | 50 | 90 | 180 |
| PTFE (polytetrafluorethylen) | 50 | 110 | 250 | 50 | 80 | 130 |
| CER (ceramica) | 60 | 120 | 150 | 60 | 90 | 150 |
| MIC (mica) | 70 | 100 | 160 | 70 | 95 | 160 |
Table of recommended flange surface finish
| roughness | value (µm) | application | ||||
| Ra | - | 3,2 | 6,3 | 12,5 | - | recommended |
| Ra | 1,6 | - | - | - | 25 | acceptable under specific conditions |
