Rubber Gate Seals ISO 9001 :

Transcription

1 Rubber Gate Seals ISO 9001 :

2 Dam Gate Seals GENERL Rubber Gate seals are manufactured from specially formulated rubber compounds giving high abrasion resistance, flexibility and efficient sealing. The high flexibility of Rubber Gate seals results in overcoming inaccuracies due to allowable tolerances of construction, fabrication and erection of Gate / guide plates. The gate seal accommodates itself to the normal variations arising from thermal expansion / contraction, load deflections, etc., ensuring adequate and effective sealing. Rubber Gate seals are manufactured for all applications in the widest range of types, shapes and sizes catering to the requirements of all Irrigation and Hydro electric Projects. TYPES Plain Type rass / Stainless Steel Cladded brasion Resistant Fluorocarbon ( PTFE / Teflon ) Cladded PLIN RUER SELS These are available in all standard shapes and sizes viz., Flat Type, `P /`J /Musical Note Type, Double Stem Type, Double ulb Type, `L /`Z Type and special section seals. METL CLDDED RUER SELS Rubber Seals are metal cladded to reduce the friction during gate operation. Metal cladding also reduces and checks the tendency of rubber bulb to extrude in available spaces or gaps due to high water pressure during opening and closing of gate. The rigidity of metal cladding however, reduces the flexibility of the seal as compared to plain rubber seals or Fluorocarbon Film cladded rubber seals. Metal cladding may have center or edge slotting to reduce rigidity. Thickness of metal cladding normally provided is 1.5 mm to 3.0 mm. Metal cladded seals are manufactured in rass, ronze or Stainless Steel. FLUOROCRON FILM CLDDED RUER SELS Fluorocarbon Film Cladded Seals offer the advantage of extremely low coefficient of friction. The Fluorocarbon Film is moulded along with the rubber component of the gate seal making it an integral part of the seal. The Fluorocarbon Film does not project above the bulb surface since it is recessed into the rubber as it is with metal cladding. The high flexibility of specially formulated rubber compound of gate seal and the extremely low coefficient of friction of fluorocarbon film results in substantial reduction of frictional load, and thereby, hoists of reduced capacity can be used. Fluorocarbon Film Cladded Rubber Gate Seals should never be bent or skewed during storage, transportation and erection. They should preferably be transported on wooden planks or by using similar methods to keep the cladding straight. ending or skewing in not a method to test the bond strength.

3 Dam Gate Seals MNUFCTURING PROCESS Rubber Gate seals are manufactured by two manufacturing processes viz., extrusion and moulding. EXTRUSION: Extrusion is the cheapest method of manufacture of rubber gate seals. Expensive moulds are not required. However, close tolerances are difficult to maintain. Maintaining uniform cross section throughout the length of the gate seal is difficult to achieve thereby, non uniform pre compression of the gate seals is observed. Cladded gate seals cannot be manufactured by this process. MOULDING: Rubber gate seals are manufactured in moulds whereby, a uniform cross section through out the length of the gate seal is attained. Close tolerances can be achieved by this process. There is better control over the quality and size of the gate seal. SHPES Rubber Gate seals are available in the widest range of shapes. Since every Irrigation / Hydroelectric Project has its own design requirements, if the shape required does not fall in the existing range, gate seals of special sections as per the customer s specifications are also manufactured. Flat Type Rectangular Half round at one end Wedge Type `P /`J /Musical Note Type* Solid ulb Hollow ulb Double Stem Type* Solid ulb Hollow ulb Double ulb Type* Solid ulb Hollow ulb `L /`Z Type Seals Special Section Seals * Corner Seals 2 Dimensional 3 Dimensional ( * indicates with / without cladding)

4 Dam Gate Seals GTESEL SPECIFICTIONS S PER INDIN STNDRDS IS: 11855:1986 RUER: Hardness : Shore ` : 65 ± 5 Tensile Strength : N/mm2 : 14.5 Elongation at reak : % : 450 Water bsorption : % by wt. : < 10% Oxygen geing : : > 80% of value of Tensile strength before ageing RUER METL DHESION TEST: Tensile Strength : N/cm : 176 RUER FLUOROCRON FILM DHESION TEST: Tensile Strength : N/cm : 54 INTERNTIONL STNDRDS STM RUER: Hardness : Shore ` : 65 ± 5 Tensile Strength : lb/in2 : 3000 Elongation at reak : % : 450 minimum Water bsorption : % by wt. : < 5 Compression set : % : 30 maximum Oxygen geing : % FLUOROCRON FILM: Tensile Strength : psi : 2000 : > 80% of value of Tensile strength before ageing Elongation at reak : % : 250 minimum RUER METL DHESION TEST: Tensile Strength : lb/inch width : 100 RUER FLUOROCRON FILM DHESION TEST: Tensile Strength : lb/inch width : 30

5 Dam Gate Seals GTESEL LENGTHS Plain rubber gate seals are supplied in desired lengths. The essential criteria for deciding the length of such seals is the weight of the roll, ease in transportation and handling. Metal cladded rubber seals should not be bent or skewed. Metal cladded rubber seals are supplied in maximum lengths of 5.0 meters. The limitation being with regard to the maximum lengths that can be accommodated in normal trucks. Fluorocarbon Film cladded rubber seals cannot be bent or skewed as with metal cladded rubber seals. They are supplied in either: a. Maximum straight lengths of 5.0 meters and parts thereof (refer Drg. # I 24). The total desired length of the gate seal can be made up of such lengths and jointed at site using any of the jointing methods (see `jointing of rubber gate seals ). b. Fluorocarbon Film though having the lowest coefficient of friction, has its own limitation. It is a plastic material having limited modulus of elasticity. Thus, when a Fluorocarbon Film is stretched beyond its elastic limit, severe localized stress may occur, cannot regain its original dimension and leads to permanent deformation. This limitation is also applicable to Fluorocarbon Film Cladded Rubber Gate Seals whereby the Fluorocarbon Film and the bonding gets permanently damaged. In order to overcome this, the total Fluorocarbon cladding length is divided into smaller lengths with a `non fluorocarbon portion of about ½, comprising of rubber and matching the fluorocarbon film cross section. When lowering / raising the gate, corner seals are subjected to maximum stress in the complete rubber seal assembly Corner seals should be single piece moulded type only. JOINTING OF RUER GTESELS Plain rubber seals are easy to joint. However, with Fluorocarbon Film Cladded seals up to 5.0 meters, it is imperative to understand the problem associated with it. Fluorocarbon Film is a non stick material and jointed using specialized techniques at the factory. It is virtually not possible to bond the exposed Fluorocarbon Film section to Fluorocarbon Film at both ends of seal lengths at site (refer Fig. #1a, Drg. #24). While attempting to bond such exposed sections, only the rubber section can be cemented with the fluorocarbon film section thickness unbonded. Leakages occur through such unbonded fluorocarbon film thickness sections of the seals under medium to high heads. The force exerted at such minute areas being high enough for fluorocarbon film bonding failure to occur over a period of time. The problem is overcome by providing a `nonfluorocarbon length of apprx. ½ at the seal ends to attain a total rubber rubber bond (refer Fig. #1b, Drg. #24). There is no significant increase in the co efficient of friction since the `non fluorocarbon length is negligible as compared to the total seal length. ll Rubber Rubber joints are stronger, reliable and can be easily executed at site. dditional extra length of rubber portion is provided for `Shop Trimming at site to achieve the exact desired total seal length.

6 Dam Gate Seals Splicing and site jointing of rubber gate seals can be carried out by various methods: dhesive splice joint Vulcanized splice joint DHESIVE SPLICE JOINT dhesive splice joint procedures are adopted at locations where vulcanized splicing is not possible. ll seals to be correctly punched cut to true length and fully fitted to the gate during shop assembly fusing the gate and clamp plate as templates. ll seal joints to be butted up square with no visible gaps or steps in seal contact faces. On final site assembly, all seal joints are treated with a cyanoacrylate adhesive having maximum strength with longest open times. VULCNISED SPLICE JOINT Jointing of rubber seals at the gate fabricator s workshop or at site, vulcanized splice joints give the best results. For making vulcanized splice joints, moulds, equipments, tools and rubber raw materials are required. The jointing is carried out in heated moulds with raw rubber compound used in between. est joint strengths (almost equal to the original seal) are achievable. For cladded seal jointing at site, the procedure is the same. The cladding, however, will not be continuous at the joint. There will be a gap of about 6 to 12 mm between the cladding at the joint. The gap will however have rubber in between matching the cross section of the seal except for the shrinkage of the fresh rubber compound. The shrinkage however is very negligible and is accommodated during seal compression resulting in no leakage. Rubber gate seals cladded or plain should never be bent at the joints. Vulcanising equipment complete with vulcanizing press, moulds, rubber compounds, splicing tools etc., are available.

7 Flat Type Rubber Seals c c D T Y P E F 1 TYPE F1 / F2 / F3 / F4 TYPE F1 / F2 / F3 / F4 c D TYPE F1 / F2 / F3 / F4 c D TYPE F1 / F2 / F3 / F4 C D TYPE F1 / F2 / F3 / F4 TYPE F1 c

8 P / J Type Rubber Seals C D

9 L / Z Type Rubber Seals

10 L / Z Type Rubber Seals

11 L / Z Type Rubber Seals

12 L / Z Type Rubber Seals

13 L / Z Type Rubber Seals

14 L / Z Type Rubber Seals

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