What factors should be considered when selecting a valve?

Consider valve type, pressure and temperature ratings, material compatibility with your fluid, actuation method (manual or automatic), and maintenance requirements.

How do valves control fluid flow?

Valves regulate flow by opening, closing, or partially obstructing the pathway. Their mechanisms (such as the rotation of a ball or the linear movement of a gate) determine the speed and precision of flow control.

What is a flange and how does it function in piping?

A flange is a flat, circular component used to connect pipes, valves, or other equipment. Bolted together with gaskets, flanges provide a secure, leak-proof joint that facilitates both assembly and maintenance.

What is the difference between manual and actuated valves?

Manual valves require physical operation via handles or levers, whereas actuated valves use mechanisms—pneumatic, electric, or hydraulic—to open and close automatically or remotely.

What are common issues or failures encountered with valves and pipe fittings?

Issues include leaks caused by improper installation, over-tightening, degraded seals, material incompatibility, and fatigue from repeated cycling. Regular inspection and proper installation practices help mitigate these problems.

How should valves and pipe fittings be maintained?

Regular maintenance involves periodic inspections, cleaning or replacing worn seals, ensuring proper torque during installation, and adhering to manufacturer guidelines and local plumbing codes to preserve system integrity.

Silicone Rubber (Si) O-Rings (0.275 Section)

Silicone Rubber (Si) O-Rings (0.275 Section): Versatile Sealing Performance Across Extreme Temperatures

Silicone Rubber (Si) O-Rings (0.275 section) from TFM are engineered for reliable performance in environments requiring high flexibility, broad thermal stability, and resistance to ozone and weathering. Manufactured from high-quality 1200-70 grade silicone, these O-rings are ideal for sealing in low-pressure gas systems, vacuum components, and equipment exposed to thermal cycling.

With a 70 durometer hardness and brick red coloration, these O-rings deliver consistent compression and excellent sealing performance across a temperature range from -50°C to 230°C. While they are not designed for high shear or tensile stress environments, they excel in static sealing applications and are widely used in UHV, semiconductor, and analytical systems.

Key Features of Silicone Rubber (Si) O-Rings (0.275 Section):

Material Grade: 1200-70 Silicone
Color: Brick Red
Durometer Hardness: 70 Shore A
Cross-Section: 0.275 inches
Temperature Range:
- Minimum: -50°C (ideal for cryogenic and low-temperature sealing)
- Maximum: +230°C (suitable for moderate bakeouts and thermal cycling)
Chemical Resistance:
- Excellent: Ozone, oxygen, water, dilute acids
- Good: Weathering, aging, UV exposure
- Poor: Petroleum oils, fuels, and strong solvents
Applications:
- Sealing vacuum chamber viewports and feedthroughs
- Use in UHV systems and cleanroom assemblies
- Analytical instruments exposed to ambient atmospheric cycles
- Light mechanical seals in HVAC, pharmaceutical, and food-grade processing systems

Why Choose TFM’s Silicone Rubber O-Rings?

TFM’s silicone O-rings are precisely manufactured to meet industrial sealing demands in environments where thermal resistance and ozone stability are critical. While not suited for dynamic or high-mechanical-load conditions, these 0.275-inch section silicone O-rings are the preferred solution for static seals under vacuum, pressure, or atmospheric exposure.

Ordering Table

Drawing	Reference	O-Ring Size	O-Ring Material	O-Ring OD	O-Ring ID	O-Ring Cross Section	O-Ring Color	Part Number
	O-ring Seals, Silicone	400	1200-70 Silicone	1.900	1.350	0.275	Brick Red	O-S400
	O-ring Seals, Silicone	401	1200-70 Silicone	2.025	1.475	0.275	Brick Red	O-S401
	O-ring Seals, Silicone	402	1200-70 Silicone	2.150	1.600	0.275	Brick Red	O-S402
	O-ring Seals, Silicone	403	1200-70 Silicone	2.275	1.725	0.275	Brick Red	O-S403
	O-ring Seals, Silicone	404	1200-70 Silicone	2.400	1.850	0.275	Brick Red	O-S404
	O-ring Seals, Silicone	405	1200-70 Silicone	2.525	1.975	0.275	Brick Red	O-S405
	O-ring Seals, Silicone	406	1200-70 Silicone	2.650	2.100	0.275	Brick Red	O-S406
	O-ring Seals, Silicone	407	1200-70 Silicone	2.775	2.225	0.275	Brick Red	O-S407
	O-ring Seals, Silicone	408	1200-70 Silicone	2.900	2.350	0.275	Brick Red	O-S408
	O-ring Seals, Silicone	409	1200-70 Silicone	3.025	2.475	0.275	Brick Red	O-S409
	O-ring Seals, Silicone	410	1200-70 Silicone	3.150	2.600	0.275	Brick Red	O-S410
	O-ring Seals, Silicone	411	1200-70 Silicone	3.275	2.725	0.275	Brick Red	O-S411
	O-ring Seals, Silicone	412	1200-70 Silicone	3.400	2.850	0.275	Brick Red	O-S412
	O-ring Seals, Silicone	413	1200-70 Silicone	3.525	2.975	0.275	Brick Red	O-S413
	O-ring Seals, Silicone	414	1200-70 Silicone	3.650	3.100	0.275	Brick Red	O-S414
	O-ring Seals, Silicone	415	1200-70 Silicone	3.775	3.225	0.275	Brick Red	O-S415
	O-ring Seals, Silicone	416	1200-70 Silicone	3.900	3.350	0.275	Brick Red	O-S416
	O-ring Seals, Silicone	417	1200-70 Silicone	4.025	3.475	0.275	Brick Red	O-S417
	O-ring Seals, Silicone	418	1200-70 Silicone	4.150	3.600	0.275	Brick Red	O-S418
	O-ring Seals, Silicone	419	1200-70 Silicone	4.275	3.725	0.275	Brick Red	O-S419
	O-ring Seals, Silicone	420	1200-70 Silicone	4.400	3.850	0.275	Brick Red	O-S420
	O-ring Seals, Silicone	421	1200-70 Silicone	4.525	3.975	0.275	Brick Red	O-S421
	O-ring Seals, Silicone	422	1200-70 Silicone	4.650	4.100	0.275	Brick Red	O-S422
	O-ring Seals, Silicone	423	1200-70 Silicone	4.775	4.225	0.275	Brick Red	O-S423
	O-ring Seals, Silicone	424	1200-70 Silicone	4.900	4.350	0.275	Brick Red	O-S424
	O-ring Seals, Silicone	425	1200-70 Silicone	5.025	4.475	0.275	Brick Red	O-S425
	O-ring Seals, Silicone	426	1200-70 Silicone	5.150	4.600	0.275	Brick Red	O-S426
	O-ring Seals, Silicone	427	1200-70 Silicone	5.275	4.725	0.275	Brick Red	O-S427
	O-ring Seals, Silicone	428	1200-70 Silicone	5.400	4.850	0.275	Brick Red	O-S428
	O-ring Seals, Silicone	429	1200-70 Silicone	5.525	4.975	0.275	Brick Red	O-S429
	O-ring Seals, Silicone	430	1200-70 Silicone	5.650	5.100	0.275	Brick Red	O-S430
	O-ring Seals, Silicone	431	1200-70 Silicone	5.775	5.225	0.275	Brick Red	O-S431
	O-ring Seals, Silicone	432	1200-70 Silicone	5.900	5.350	0.275	Brick Red	O-S432
	O-ring Seals, Silicone	433	1200-70 Silicone	6.025	5.475	0.275	Brick Red	O-S433
	O-ring Seals, Silicone	434	1200-70 Silicone	6.150	5.600	0.275	Brick Red	O-S434
	O-ring Seals, Silicone	435	1200-70 Silicone	6.275	5.725	0.275	Brick Red	O-S435
	O-ring Seals, Silicone	436	1200-70 Silicone	6.400	5.850	0.275	Brick Red	O-S436
	O-ring Seals, Silicone	437	1200-70 Silicone	6.525	5.975	0.275	Brick Red	O-S437
	O-ring Seals, Silicone	438	1200-70 Silicone	6.775	6.225	0.275	Brick Red	O-S438
	O-ring Seals, Silicone	439	1200-70 Silicone	7.025	6.475	0.275	Brick Red	O-S439
	O-ring Seals, Silicone	440	1200-70 Silicone	7.275	6.725	0.275	Brick Red	O-S440
	O-ring Seals, Silicone	441	1200-70 Silicone	7.525	6.975	0.275	Brick Red	O-S441
	O-ring Seals, Silicone	442	1200-70 Silicone	7.775	7.225	0.275	Brick Red	O-S442
	O-ring Seals, Silicone	443	1200-70 Silicone	8.025	7.475	0.275	Brick Red	O-S443
	O-ring Seals, Silicone	444	1200-70 Silicone	8.275	7.725	0.275	Brick Red	O-S444
	O-ring Seals, Silicone	445	1200-70 Silicone	8.525	7.975	0.275	Brick Red	O-S445
	O-ring Seals, Silicone	446	1200-70 Silicone	9.025	8.475	0.275	Brick Red	O-S446
	O-ring Seals, Silicone	447	1200-70 Silicone	9.525	8.975	0.275	Brick Red	O-S447
	O-ring Seals, Silicone	448	1200-70 Silicone	10.025	9.475	0.275	Brick Red	O-S448
	O-ring Seals, Silicone	449	1200-70 Silicone	10.525	9.975	0.275	Brick Red	O-S449
	O-ring Seals, Silicone	450	1200-70 Silicone	11.025	10.475	0.275	Brick Red	O-S450
	O-ring Seals, Silicone	451	1200-70 Silicone	11.525	10.975	0.275	Brick Red	O-S451
	O-ring Seals, Silicone	452	1200-70 Silicone	12.025	11.475	0.275	Brick Red	O-S452
	O-ring Seals, Silicone	453	1200-70 Silicone	12.525	11.975	0.275	Brick Red	O-S453
	O-ring Seals, Silicone	454	1200-70 Silicone	13.025	12.475	0.275	Brick Red	O-S454
	O-ring Seals, Silicone	455	1200-70 Silicone	13.525	12.975	0.275	Brick Red	O-S455
	O-ring Seals, Silicone	456	1200-70 Silicone	14.007	13.457	0.275	Brick Red	O-S456
	O-ring Seals, Silicone	457	1200-70 Silicone	14.525	13.975	0.275	Brick Red	O-S457
	O-ring Seals, Silicone	458	1200-70 Silicone	15.025	14.475	0.275	Brick Red	O-S458
	O-ring Seals, Silicone	459	1200-70 Silicone	15.525	14.975	0.275	Brick Red	O-S459
	O-ring Seals, Silicone	460	1200-70 Silicone	16.025	15.475	0.275	Brick Red	O-S460
	O-ring Seals, Silicone	461	1200-70 Silicone	16.505	15.955	0.275	Brick Red	O-S461
	O-ring Seals, Silicone	462	1200-70 Silicone	17.005	16.455	0.275	Brick Red	O-S462
	O-ring Seals, Silicone	463	1200-70 Silicone	17.505	16.955	0.275	Brick Red	O-S463
	O-ring Seals, Silicone	464	1200-70 Silicone	18.005	17.455	0.275	Brick Red	O-S464
	O-ring Seals, Silicone	465	1200-70 Silicone	18.505	17.955	0.275	Brick Red	O-S465
	O-ring Seals, Silicone	466	1200-70 Silicone	19.005	18.455	0.275	Brick Red	O-S466
	O-ring Seals, Silicone	467	1200-70 Silicone	19.505	18.955	0.275	Brick Red	O-S467
	O-ring Seals, Silicone	468	1200-70 Silicone	20.005	19.455	0.275	Brick Red	O-S468
	O-ring Seals, Silicone	469	1200-70 Silicone	20.505	19.955	0.275	Brick Red	O-S469
	O-ring Seals, Silicone	470	1200-70 Silicone	21.505	20.955	0.275	Brick Red	O-S470
	O-ring Seals, Silicone	471	1200-70 Silicone	22.505	21.955	0.275	Brick Red	O-S471
	O-ring Seals, Silicone	472	1200-70 Silicone	23.490	22.940	0.275	Brick Red	O-S472
	O-ring Seals, Silicone	473	1200-70 Silicone	24.490	23.940	0.275	Brick Red	O-S473
	O-ring Seals, Silicone	474	1200-70 Silicone	25.490	24.940	0.275	Brick Red	O-S474
	O-ring Seals, Silicone	475	1200-70 Silicone	26.490	25.940	0.275	Brick Red	O-S475