product description
A figure 8 blind is a simple valve that is placed in the line between two flanges and bolted in place. One side of Figure 8 blind flange is open, known as a spacer, while the other side is blanked or blinded with a spade.
A blind flange is a safety device used to isolate equipment or lines when they need to be inspected or taken out of service. This unique flange is designed to temporarily or permanently shut off a pipeline for maintenance, repair, or modification without interrupting the flow of fluid or gas.
To change the valve from open to closed, all bolts except the pivot bolt are removed, and the Spectacle Blind is rotated on its center hole so that the blind side is between the flanges. The bolts are then re-installed and tightened, and the side that protrudes out of the pipe indicates whether the pipe is open or closed.
This valve is commonly used for maintenance purposes when a section of pipe or a device needs to be isolated. Because this isolation is semi-permanent, it is considered a safe option, and safety is a primary consideration when using a Figure 8 blind flange in maintenance operations. Moreover, these Figure 8 blind flanges are inexpensive and sturdy compared to traditional valves.
Spectacle shutter thickness is specified based on line pressure and pipe size. Changhao manufactures a wide range of high-quality blind flanges in China. We supply flanges to ASME/ANSI/DIN standards.
Standard: ASNI/ASTM B16.5 / 16.36/16.47A/16.47B B2220 – 2001, DIN2527/2636/2637/2638/2566/2576/2633/2635/2642/2653/2655.
Pressure Rate: 150LBS to 2500LBS / PN10 to PN400
Dimension: 1/2" to 48"
Material: Carbon steel, Alloy Steel, Stainless steel.
Sealing type: RF, FF, MFM, TG, RTJ
Pressure rating:
class 150LBS、300LBS、400LBS、600LBS、900LBS、1500LBS、2500LBS
Dimensions:
ANSI B16.5, ANSI B16.47, MSS SP44, ANSI B16.36, ANSI B16.48, API 605, AWWA AND DRAWING
Material:
· CS
Standard: ASTM / ASME A/SA 105 / 350 LF 2
· SS
Standards: ASTM / ASME A/SA 182
Steel Grade: F 304, 304L, 304H, 309S, 309H, 310S, 310H, 316, 316TI, 316H, 316L, 316LN, 317, 317L, 321, 321H, 347, 347H, 904L.
· AS
Standard: ASTM / ASME A/SA 182
ASTM A182 F1, F11, F12, F22, F5, F9, F91.
· Nickel Alloy
Standard: ASTM / ASME SB 564 / 160 / 472
Grade: UNS 2200 (NICKEL 200), UNS 4400 (MONEL 400), UNS 8825 INCONEL (825), UNS 6600 (INCONEL 600), UNS 6601 (INCONEL 601), UNS 6625 (INCONEL 625), UNS 10276 (HASTELLOY C 276), UNS 2201 (NICKEL 201), (ALLOY 20 / 20 CB 3)
The figure 8 blind, also known as spectacle blinds, is a two-piece flange assembly consisting of a blind flange and a spacer flange. One of the main advantages is the ability to temporarily or permanently shut off a pipe using a blind flange. This is particularly useful in situations where maintenance or repair of the pipeline is required, as it eliminates the need for downtime, which can be both time-consuming and expensive.
Another advantage of eyeglass blind flanges is their flexibility. They can be easily installed and removed, allowing for quick changes to the piping configuration. This is particularly useful in situations where fluid or gas flow needs to be redirected or transferred to another pipeline.
Spectacle blind flanges are also cost-effective. They eliminate the need for costly downtime, disassembly and reassembly of the entire piping system. This can save a company a great deal of time and money.
There are several factors to consider when choosing the right cobra blind flange for your piping system. These include
Material
The material of the flange should be compatible with the material of the piping and the fluid or gas being transported.
Size
The size of the flange should match the size of the piping to ensure a secure and leak-free connection.
Pressure Rating
Flanges should be rated to withstand the maximum pressure of the piping system.
Temperature Ratings
Flanges shall be rated to withstand the maximum temperature of the piping system.
Corrosion Resistance
Flanges should be corrosion-resistant to ensure that they will not corrode over time, leading to leaks and other safety hazards.
Spectacle blind flanges are used in a variety of industries, including oil and gas, chemical, petrochemical and power generation. In the oil and gas industry, blind flanges are used to isolate sections of pipe during maintenance and repair operations. In the chemical industry, they are used to divert chemical flows to different pipelines. In the petrochemical industry, they are used to isolate pipeline sections during maintenance and to prevent product contamination. In the power generation industry, they are used to isolate pipe sections during maintenance and to redirect steam flow to different turbines.
Spectacle blind flanges are also used in other industries, such as food processing, pharmaceuticals and water treatment. In the food processing industry, they are used to isolate sections of piping during cleaning and sterilization operations. In the pharmaceutical industry, they are used to isolate pipe sections during the production process and to prevent product contamination. In the water treatment industry, they are used to isolate pipe sections during maintenance and to divert water flow to different treatment processes.
Spectacle blind flanges are available at very affordable prices.
Please click here to request an updated price list and information on readily available stock and your requirements. Changhao has all standard products in stock and can export them at the best prices.
As a Chinese manufacturer, Changhao is able to manufacture the Figure 8 blind using test materials that meet customer specifications. typically, the Figure 8 blind is made of carbon steel, alloy steel, or stainless steel. Whether you want figure 8 blind flange protection for 2 weeks or 2 years, Changhao has a packaging system that will ensure that the eyeglass blinds are installed intact. If more robust corrosion protection is required, our sales team will be happy to provide more information.
In addition, specific engineering requirements may dictate that special materials and constructions are required to produce the Figure 8 blind flange. As a fully ISO 9001-certified manufacturer, Changhao can customize products according to your specifications, including thorough testing and documentation. Changhao's system tracks all materials, and upon request, we can provide ITP and MDR. Your order can be packaged to your engineering or project specifications, and we can accommodate extremely short lead times.
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