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Oil leakage
news [ndt AP-- - ONS WELDING INSTITUTE CONTRACT A two y e a r r e s e a r c h p r o g r a m m e on acoustic e m i s sion is to be undertaken by the Welding Institute, under the sponsorship of the Ministry of Defence (Navy). Acoustic emission equipment developed at the Admiralty Materials L a b o r a t o r y will be loaned to the Welding Institute for this £ 2 5 , 0 0 0 - p r o j e c t . The initial evaluation of the acoustic emission technique will be made with a range of high strength m a t e r i a l s and various welding p r o c e s s e s , using standard cracking test specimens that can produce known defects and which can be examined by conventional non-destructive and destructive tests such as x - r a y , ultrasonic and metallographic examination-using both optical and scanning electron m i c r o s c o p e s . This part of the work will attempt to c o r r e l a t e the total s t r e s s wave emission registration with an estimate of the weld quality or c r a c k size. F r o m this initial study, it is expected that an equipment can be specified which will be robust and reliable and capable of operating in a welding environment. The second part of the p r o g r a m m e will determine the feasibility of locating defects in situ during welding, and whether an indication of their type or significance can be obtained. The equipment will be developed to eliminate or suppress common s o u r c e s of a r c noise and disturbances due to metal t r a n s f e r , if these interfere with interpretation of acoustic emission.
The resultant information is automatically r e c o r d e d by the Static Devices unit. P r i n t - o u t is on both a teleprinter and 1-in 8-hole coded paper tape. The whole of the rocket motor is systematically inspected, and recording is continuous. Static Devices Limited, North Bar Place, Banbury, Oxon, UK
OIL LEAKAGE Oil leaking past the sealing lip of a g a r t e r seal into a g r e a s e packed bearing has been detected using fluor e s c e n t t r a c e r s . The Skefko Ball Bearing Co have added fluorescent t r a c e r to the oil to be retained by the sealing lip of a g a r t e r seal on a g r e a s e packed bearing (Fig 1). The oil that leaked past the seal was detected using an ultraviolet lamp. This had p r e viously been a problem as small quantities of oil leaking through the seal became mixed with the g r e a s e and could therefore not be positively identified. Useful information on the cause of the leakage can be obtained by intelligent reading of the location and amount of the treated oil which has been leaked. The t r a c e r used is Zyglo leaker penetrant ZL7, oil soluble, supplied by Magnaflux Ltd of London. A concentration of 1/3 oz of ZL7 to one gallon of oil was found to be suitable. Skefko Ball Bearing Company Ltd, Luton, UK
The Welding Institute, Abington Hall, Abington, Cambridge CB1 6AL, UK
SOLID-PROPELLANTROCKET
MOTORS EXAMINED
An u l t r a s o n i c / e l e c t r o n i c s y s t e m for the inspection of solid-propellant rocket m o t o r s has been produced at the Ministry of Defence Rocket Propulsion Establishment at Westcott. The system c o n s i s t s of multiple p i e z o - e l e c t r i c t r a n s d u c e r s which send low-frequency pulses (350 KHz) through the r o c k e t body, to be received by a similar t r a n s d u c e r inside the body. An integral p a r t of the new s y s t e m is a digital data acquisition unit, made by Static Devices, Banbury, which provides continuous automatic r e c o r d i n g of data from the r o c k e t m o t o r under test, and enables an a c c u r a t e picture to be gained of the state of the p r o peUent and its surrotmding insulation and case. Flaws, cavities, a r e a s of porosity or other discontinuities in the solid propellent, and adhesion flaws between the insulation and propellent and case may cause m o t o r malfunction which in an e x t r e m e case could result in a rocket m o t o r exploding. Not only dangerous, but highly expensive should this happen on a launcher.
Fig 1 R e s e a r c h technician using an ultraviolet lamp to detect oil treated with a fluorescent tracer non-destructive testing August 1971
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The resultant information is automatically r e c o r d e d by the Static Devices unit. P r i n t - o u t is on both a teleprinter and 1-in 8-hole coded paper tape. The whole of the rocket motor is systematically inspected, and recording is continuous. Static Devices Limited, North Bar Place, Banbury, Oxon, UK
OIL LEAKAGE Oil leaking past the sealing lip of a g a r t e r seal into a g r e a s e packed bearing has been detected using fluor e s c e n t t r a c e r s . The Skefko Ball Bearing Co have added fluorescent t r a c e r to the oil to be retained by the sealing lip of a g a r t e r seal on a g r e a s e packed bearing (Fig 1). The oil that leaked past the seal was detected using an ultraviolet lamp. This had p r e viously been a problem as small quantities of oil leaking through the seal became mixed with the g r e a s e and could therefore not be positively identified. Useful information on the cause of the leakage can be obtained by intelligent reading of the location and amount of the treated oil which has been leaked. The t r a c e r used is Zyglo leaker penetrant ZL7, oil soluble, supplied by Magnaflux Ltd of London. A concentration of 1/3 oz of ZL7 to one gallon of oil was found to be suitable. Skefko Ball Bearing Company Ltd, Luton, UK
The Welding Institute, Abington Hall, Abington, Cambridge CB1 6AL, UK
SOLID-PROPELLANTROCKET
MOTORS EXAMINED
An u l t r a s o n i c / e l e c t r o n i c s y s t e m for the inspection of solid-propellant rocket m o t o r s has been produced at the Ministry of Defence Rocket Propulsion Establishment at Westcott. The system c o n s i s t s of multiple p i e z o - e l e c t r i c t r a n s d u c e r s which send low-frequency pulses (350 KHz) through the r o c k e t body, to be received by a similar t r a n s d u c e r inside the body. An integral p a r t of the new s y s t e m is a digital data acquisition unit, made by Static Devices, Banbury, which provides continuous automatic r e c o r d i n g of data from the r o c k e t m o t o r under test, and enables an a c c u r a t e picture to be gained of the state of the p r o peUent and its surrotmding insulation and case. Flaws, cavities, a r e a s of porosity or other discontinuities in the solid propellent, and adhesion flaws between the insulation and propellent and case may cause m o t o r malfunction which in an e x t r e m e case could result in a rocket m o t o r exploding. Not only dangerous, but highly expensive should this happen on a launcher.
Fig 1 R e s e a r c h technician using an ultraviolet lamp to detect oil treated with a fluorescent tracer non-destructive testing August 1971
229