A gate valve, also known as a sluice valve, is a valve that opens by lifting a round or rectangular gate/wedge out of the path of the fluid. The distinct feature of a gate valve is the sealing surfaces between the gate and seats are planar, so gate valves are often used when a straight-line flow of fluid and minimum restric tion is desired. The gate faces can form a wedge shape or they can be parallel. Typical gate valves should never be used for regulating flow, unless they are specifically designed for that purpose. On opening the gate valve, the flow path is enlarged in a highly nonlinear manner with respect to percent of opening. This means that flow rate does not change evenly with stem travel. Also, a partially open gate disk tends to vibrate from the fluid flow. Most of the flow change occurs near shutoff with a relatively high fluid velocity causing disk and seat wear and eventual leakage if used to regulate flow. Typical gate valves are designed to be fully opened or closed.[1] When fully open, the typical gate valve has no obstruction in the flow path, resulting in very low friction loss[2]. Gate valves are characterised as having either a rising or a nonrising stem. Rising stems provide a visual indication of valve position because the stem is attached to the gate such that the gate and stem rise and lower together as the valve is operated. Nonrising stem valves may have a pointer threaded onto the upper end of the stem to indicate valve position, since the gate travels up or down the stem on the threads without raising or lowering the stem. Nonrising stems are used underground or where vertical space is limited. Bonnets provide leakproof closure for the valve body. Gate valves may have a screw-in, union, or bolted bonnet. Screw-in bonnet is the simplest, offering a durable, pressure-tight seal. Union bonnet is suitable for applications requiring frequent inspection and cleaning. It also gives the body added strength. Bolted bonnet is used for larger valves and higher pressure applications. Another type of bonnet construction in a gate valve is pressure seal bonnet. This construction is adopted for valves for high pressure service, typically in excess of 15 MPa (2250 psi). The unique feature about the pressure seal bonnet is that the body - bonnet joints seals improves as the internal pressure in the valve increases, compared to other constructions where the increase in internal pressure tends to create leaks in the body-bonnet joint. Gate valves may have flanged ends which are drilled according to pipeline compatible flange dimensional standards. Gate valves are typically constructed from cast iron, ductile iron, cast carbon steel, gun metal, stainless steel, alloy steels, and forged steels.

Frame/Fork:- Kuota Kalibur (size S) Front Wheel:- Zipp 808 Tubular Tubulars:- Zipp Tangente Dimpled Tubular Pedals:- Time RXS Carbon Crankset:- Shimano Dura-Ace 53/48T Bottom Bracket:- FSA Ceramic Bearings Chain:- Wipperman Stainless Steel - Hollow Pin Cassette:- Shimano Dura-Ace 11 - 21 Front Derailleur:- Shimano Dura-Ace (Braze On) Rear Derailleur:- Shimano Dura-Ace 10 Speed Shifters:- Shimano Dura-Ace Bar End Handlebars:- Vision Base Bar (Aluminium) Aero Bars:- Vision Carbon Pro - Racing Bend (with Armrests off Vision Mini TT Bars) Stem:- Vision Sizemore Headset:- FSA Carbon Integrated Brake Levers:- Vision Aero Brake Lever Brake Calipers:- Zero Gravity OG 06 Ti - Swiss Stop Brake Pads (Yellow) Saddle:- Fizik Arione TT Seatpost:- Kuota Carbon 74 Degree (introduced to the hacksaw) Computer:- Mavic Wintech ES (with front E-Skewer) Handlebars/Aero Bar Tape:- Non Skid Grip Tread Cabling:- All Power Cordz 5mm Cable Housing & Gear Inners (including brakes) Valve Extensions:- Vittoria (Also use a Pro (Shimano) Rear Disc & Pro 4-Rays (4 Spoke) front wheel. Has since been rebuilt with SRAM Red Componentry