Norgren Collateral

12 Solutions Q&A ? 3.2.5 Do we produce liquid (water) regulators? IMI Norgren has regulators suitable for liquids, primarily water. These include plastic bodied miniature regulators eg R91G/W and 11-044, as well as brass R06's and R43's. All are suitable for non potable water, some for potable water. Check catalog sheets for details. Water regulators can be used with other liquids but it is necessary to check corrosion resistance and material compatibility. Differences in viscosity may effect performance. Water regulators can be used on air but normally have poorer performance characteristics than air regulators. ? 3.2.6 Can we do 11-818 Precision Regulators with Gauges? Yes, we do have some special models, contact Application Engineering for details. ? 3.2.7 Can we produce reverse flow regulators? Reverse flow regulators allow the outlet pressure to flow back, through the regulator (via an internal check valve) when the inlet pressure is switched off. This is important when the regulator is placed between a valve and cylinder. This option is available in Excelon 74, 73 and 72 Series and Olympian Plus. The R07, being an unbalanced valve regulator can also be reverse flowed. 3.3 Adjustment mechanisms ? 3.3.1 What different adjustment mechanisms are available? A non-rising knob is the standard adjustment mechanism for most general purpose regulators. A T-handle will provide added leverage and is standard for regulators with 250 psig springs. They are also a common alternative to a knob in applications where the operator is wearing gloves, or has greasy hands. ? 3.3.2 What is the difference between tamper resistant, tamper evident, and tamper proof? Tamper Resistant: a device which makes alterations of set pressure difficult. Units which normally have a T-bar can have the T-bar replaced by a screw driver slotted adjusting screw over which a metal cap is fitted. In this way the set pressure can be protected from accidental adjustment. Units with adjusting knobs are made tamper resistant by preventing the knob being pulled into its unlocked position for example:- • R07 insert self tapping screw through the top of the knob. • R72/73/74/64 use tamper resistant kit and seal with a padlock or seal wire. Tamper Evident: shows if the set pressure has been altered by the breaking of a seal. Tamperproof: something which cannot be tampered with at all. It is difficult to describe anything as tamper proof because if someone is intent on making regulator adjustments then they can always find a way. As a result we do not call our regulators tamper proof. ? 3.3.3 What presetting options are available? Most regulators can be 'set' in some way, if in doubt contact IMI Norgren as this is generally a factory operation. • Max Set: unit is modified to prevent the regulator being adjusted above a specified maximum. • Min Set: unit is modified to prevent the regulator being adjusted below a specified minimum. • Min/Max Set: unit can only be adjusted between two specified upper and lower units. • Preset unit outlet pressure is set and (Factory Set): locked prior to despatch. These units are not tamper resistant (unless requested). 3.4 Regulators in applications ? 3.4.1 Can the regulators be adjusted outside the recommended range? The recommended range is that at which the regulator will perform at its optimum. These are not the maximum and minimum values. Regulators can be set outside these limits. WARNING: Outlet pressure can be adjusted to pressures in excess of, and less then, those specified. Do not use these units to control pressures outside of the specified ranges. ? 3.4.2 Will regulators shut off? Yes, screwing the adjustment 'up' (counterclockwise) closes the valve. It is possible to achieve zero psig with a regulator, however they are not designed to fulfill this function. If shut off is required use a shut off valve. ? 3.4.3 Will regulators work mounted upside down? Regulators can be mounted in any orientation without affecting their function. ? 3.4.4 How do you set a regulator? Always set on a rising pressure, i.e. on an increasing spring load. To adjust a regulator from 100 psig to 70 psig, back the regulator off to below 70 psig and adjust back up to the required pressure. ? 3.4.5 Can air regulators be used on water? Generally the answer is no for air regulators with balanced valves. It is possible with the R06 type which does not have a balanced valve and is considered dual service. See 3.2.5. ? 3.4.6 Can we use air regulators on other gases? Air regulators are generally suitable for use with C02, argon, nitrogen or other inert gases. However units are designed and tested to compressed air standards only (unless specified in the literature) and external leakage rates may vary depending on the gas involved. Compressed air regulators should never be used with flammable or noxious gases eg LPG, hydrogen etc. ? 3.4.7 Instability - what is it and how can it be prevented? Instability (humming or whistling) is the rapid cyclic fluctuation of the outlet pressure from around the set pressure. Instability is ultimately a problem occurring due to the flow path through the regulator or system. The usual solution is to change the regulator characteristics by replacing the control spring with one of a higher rating to increase the force on the diaphragm or changing the diaphragm material. There is no magic answer, it is a case of trial and error in those applications where instability occurs. ? 3.4.8 What is a constant bleed regulator? Constant bleed in regulators is designed to provide improved response. A hissing noise is normal. R24 and 11-018 are all constant bleed regulators. Regulators (cont.)

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