AIR DRIVEN GAS BOOSTERS
16Pages

CONTENTS Principle of Operation, Benefits, Features, Typical Gas Booster Applications Why Use Air Driven Gas Boosters?, International Equivalents How Do Buyers Choose Between Gas Booster Models? Determining the Proper Gas Booster Model—Examples Gas Booster Selection Table and Notes Performance Curves Installation Dimensions, Weights Standard Modifications Hydraulics International, Inc. Overview Other HII Products

PRINCIPLE OF OPERATION An air (or gas) driven gas booster has a continuously reciprocating drive piston section directly connected to one or two gas boosting sections, as illustrated in Figure 1. The drive section includes a four-way air cycling valve and dual air pilot valves to provide the continuous reciprocation. Normally, start/stop control is accomplished by cutting off drive- or pilotair input. (For description of gas section operation, see Page 3, Volumetric Efficiency.) Maximum Gas Section Pressures vary by model and are detailed on Pages 6 and 7. Maximum Drive Section Pressure is...

WHY USE AIR DRIVEN GAS BOOSTERS? GAS PURITY: Most gases used in industry and life support must be clean and dry. Otherwise, the end use is severely compromised. Gases needing purity include argon(Ar), carbon dioxide(CO2), helium(He), hydrogen(H2), neon(Ne), nitrogen(N2), nitrous oxide(N2O), oxygen(O2) and breathing air. If gas purity is needed, all devices used to transfer gas or increase gas pressure must be completely dry and free of any lubricants. Hydraulics International, Inc.’s (HII’s) air driven gas boosters satisfy this requirement. No hydrocarbon lubrication is needed in the gas...

HOW DO BUYERS CHOOSE BETWEEN GAS BOOSTER MODELS? (continued) COMPRESSION RATIO Volumetric efficiency of gas boosters is affected by unswept space, internal leakage, and compression ratio. HII’s gas boosters are designed and manufactured to ensure unswept space is minimal and internal leakage is nonexistent. The compression ratio is therefore the most important factor to consider in selecting which HII model will provide the highest volumetric efficiency. To calculate or estimate the compression ratio, the outlet and inlet gas pressures must be known. If both outlet and inlet gas pressure...

DETERMINING THE PROPER GAS BOOSTER MODEL—EXAMPLES (continued) Example 3: You have a constant 4,000 PSI nitrogen supply (from an LN2 4,000 PSI pump and vaporizer); on a semi-monthly basis, you need to leak-check oil field valves to 17,500 PSI per API specification. Shop air drive pressure of about 100 PSI is available. Duty: moderate. Per Chart 2, Compress Factor for 17,500 PSI outlet is 550. Compress Factor for 4,000 PSI Inlet is 273 obtained by using Chart 2 or the Compress Factor for Inlet PSI equation (4014.7 PSIA/14.7 PSIA). HIGH PRESSURE VAPORIZER Compression ratio, worst case: 550...

TABLE 1. GAS BOOSTER SELECTION TABLE - SEE PAGE 8 FOR IMPORTANT NOTES Model (Note: Final Dash No. is Area Ratio) Approximate Stall Point: Schematic Symbol Area Ratio x Drive Air PSI Assist Factor x Gas Inlet PSI Approximate Practical Pressures Based on 95 PSI Drive, 50% Efficiency w/N2 Outlet PSI (Max) Inlet PSI (Min) Maximum Safe Pressure(a) PSI Outlet Single Acting, Single Drive (Single Stage) 1. 7 x Drive Air (No assist from gas inlet) 14 x Drive Air (No assist from gas inlet) 30 x Drive Air (No assist from gas inlet) 50 x Drive Air (No assist from gas inlet) 75 x Drive Air (No assist...

Approximate Envelope Dimensions—Inches Length, Height, Width & Weight Model Designation System (See Page 13 & 14 for more details) Port Detail BOX 5: Modifications (See Page 15) N - Lapped Cycling Valve Assembly O - Oxygen Gas Service to 5,000 PSI V - Viton Seals in the Air Drive Section X - External Pilot Port on Air Drive Section BOX 4: Ratio—Two Stage Boosters Only Nominal First Stage Area Ratio/Second Stage Area Ratio BOX 1: Gas Booster Type S - Single Acting D - Double Acting T - Two Stage BOX 2: Air Drive Option S - Single Drive Section D - Double Drive Section BOX 3: Ratio—Single...

TABLE 1 NOTES (a) Maximum safe pressure, (Page 6) is based on a minimum 4:1 safety factor of the ultimate strength of the hardware exposed to this pressure. But this safe pressure could be exceeded due to external sources, such as thermal expansion or the use of other inlet boosters or compressors, or due to the action of the booster itself (e.g., high inlet pressure or high drive pressure). In these cases, safety relief valve or rupture disk protection must be provided. Table 2. Net Ratios and Assist Factor of Two Stage Models Model 5G-TS-7/14 Maximum potential interstage pressure = Air...

HOW TO USE THE PERFORMANCE CURVES SINGLE UNIT Use the curves on Pages 10-12 for rough estimates only; gas booster applications that have constant gas inlet and outlet pressures are rare. Examples 1 and 2 on Page 4 represent more common situations. In Example 1, pressure is equalized across the booster so that inlet and outlet pressures are the same. Then as the booster cycles, inlet pressure continually decreases while outlet pressure continually increases. The momentary outlet flow at a fixed inlet-outlet pressure combination is not important to prospective users—but the average of a...

PERFORMANCE CURVES—Assume an air drive source of approximately 95 PSI from 1/2” ID piping. GAS OUTLET FLOW - SCFM GAS OUTLET FLOW - SCFM GAS OUTLET FLOW - SCFM GAS OUTLET FLOW - SCFM GAS OUTLET FLOW - SCFM Dashed lines represent approximate air drive consumption (A) 15 SCFM (B) 30 SCFM (C) 50 SCFM (D) 75 SCFM

PERFORMANCE CURVES—Assume an air drive source of approximately 95 PSI from 1/2” ID piping. GAS OUTLET PRESSURE - PSI GAS OUTLET PRESSURE - PSI GAS OUTLET FLOW - SCFM GAS OUTLET FLOW - SCFM GAS OUTLET PRESSURE - PSI GAS OUTLET FLOW - SCFM GAS OUTLET FLOW - SCFM GAS OUTLET FLOW - SCFM Dashed lines represent approximate air drive consumption (A) 15 SCFM (B) 30 SCFM (C) 50 SCFM (D) 75 SCFM 11

PERFORMANCE CURVES—Assume an air drive source of approximately 95 PSI from 1/2” ID piping. GAS OUTLET FLOW - SCFM GAS OUTLET PRESSURE - PSI - PSI GAS OUTLET PRESSURE GAS OUTLET FLOW - SCFM GAS OUTLET FLOW - SCFM GAS OUTLET FLOW - SCFM GAS OUTLET FLOW - SCFM Dashed lines represent approximate air drive consumption (A) 15 SCFM (B) 30 SCFM (C) 50 SCFM (D) 75 SCFM