MICA SHIELDS

MICA SHIELDS provide the best protection possible, to flat transparent, sight glasses in water and liquid level gauges and columns in high pressure steam boilers. The SHIELDS retain basic strength and increase the service life of sight glasses when used at increased steam pressures and high working temperatures. MICA SHIELDS also provide perfect visibility for monitoring the natture or degree of combustion in blast furnaces of steam boilers.


Natural mica has extremely high heat resistance; transparency ; optical clarity ; flexibility ; flatness and is unbreakable. The transparency of mica is not affected by the repeated fluctuations in heating and cooling and is not attcked by most of the gases and vapours it might come into contact with. In addition, mica resists shocks, strains and vibrations and therefore can easily be used in place of glass where there is a likelyhood of exposure to radiant heat, breakage or cracking. As steam boilers are frequently shut-down and started up again, this places extreme demands on the transparent glasses fitted between CAF sealing gaskets and cushion joints of the level gauges. It is therefore essential to protect these glasses with MICA SHIELDS by fitting them on the side facing the medium chamber. MICA SHIELDS are a must where saturated steam pressure exceed 350 psi (up to 5689 psi) and working temperatures exceed 196 deg. C (up to 600 deg. C).

MICA SHIELDS also protect the inner surfaces of the transparent glasses against erosion from chemical abrasion and from corrosive chemical effects of alkaline solutions, boiler waters, caustics, hydrofluoric acids, hot concentrated phosphoric acids, sodium and potassium hydroxides and other contaminated viscous or corrosive media. It provides an excellent sealing strength against acids, sodium, water, air and oil at extreme pressures and temperatures and completely eliminates the risk of cracks, breakage, jerks, shocks, combustion effects, etc. In fact, MICA SHIELDS serve effectively in closing the spy holes of observation doors of level gauges and columns.

MICAMAFCO brand MICA SHIELDS are made of the highest quality natural muscovite sheet mica. Our SHIELDS are transparent and colourless having a high degree of through-vision transparency and thus guarantying optimum visibility of the level gauges and columns. In terms of purity, our MICA SHIELDS meet the requirements of ASTMD 351 -57T, MIL-G-18498C(SH) and ISO-2185-1972. They are supplied in any desired length, width and tickness to meet our clients specific needs. Each MICA SHIELD is rigidly tested and inspected for quality and reliability befire despatch and is supplied in individual packets to eliminate scratching and to protect them against damage. A multi- language installation and maintenance guide is included in each package.

STANDARD MICA SHIELD SIZES
NO
TYPE A/B
TYPE A
TYPE B/H
TYPE TA-28
 
L
 
B
L
 
B
L
 
B
L
 
B
O
95
X
24
95
X
30
95
X
34
  
--
 
I
115
X
24
115
X
30
115
X
34
133
X
47
II
140
X
24
140
X
30
140
X
34
158
X
47
III
165
X
24
165
X
30
165
X
34
183
X
47
IV
190
X
24
190
X
30
190
X
34
208
X
47
V
220
X
24
220
X
30
220
X
34
238
X
47
VI
250
X
24
250
X
30
250
X
34
268
X
47
VII
280
X
24
280
X
30
280
X
34
298
X
47
VIII
310
X
24
320
X
30
320
X
34
338
X
47
IX
320
X
24
340
X
30
340
X
34
358
X
47
X
340
X
24
370
X
30
370
X
34
378
X
47
XI
360
X
24
400
X
30
400
X
34
 
--
 
XII
370
X
24
430
X
30
430
X
34
 
--
 
XIII
400
X
24
460
X
30
460
X
34
 
--
 
XIV
430
X
24
500
X
30
500
X
34
 
--
 

The above dimensions are in millimetres
L=Length B=Breadth T=Thickness

Standard Thickness 0.10 - 0.15 mm/0.13 - 0.17 mm.
0.15 - 0.20 mm/0.18 - 0.22 mm
0.20 - 0.30 mm/0.30 - 0.40 mm.

Please note that the above are by no means a complete range. We are capable to supply Mica Shields in any specified size, shape and thickness as per specific requirements of our customers.

Caution: The service life of a transparent glass very much depends on the MICA SHIELD used. Once the mica is worn out, the entire assembly including the glass has to be replaced which is both a costly and complicated task. It is, therefore, adviced to use only a superior quality MICA SHIELD having accurate thickness to provide complete safety and guaranteed service life to the sight glasses. The thickness of the MICA SHIELDS are usually calculated on the basis of the steam pressures and workign temperatures. However, in no case should such thickness be calculated on the minimum (minus) values. This would result in shortening the life of a transparent glass by half or even less.

MICAMAFCO is one of the world's largest producer and supplier of a complete range of Mica and mica products including MICA SHIELDS. Our MICA SHIELDS are flawless in quality and internationally acclaimed as finest in production. We specialise in large volume production and are capable to meet our customer's specific requirements to their complete satisfaction. We are committed to a steady supply of consistent quality and are dedicated to satisfy customers who seek a most perfect material. Since the supply is Direct from Source, we are capable to offer them at cost-effective price and guaranteed delivery time.

We believe in establishing and maintaining a long term cordial trade relations with our customers and are prepared to serve you no matter how 'large' or how 'small' your requirements may be.

MICA MANUFACTURING CO. PVT.LTD.

3C, Camac Street, P.O.Box 9052,
Calcutta 700 016
INDIA
Tel: +91-33-2229-2277/2229-4505
Fax:+91-33-2229-5216/2474-7959

  E-mail :micamafco@vsnl.net