10-year shelf life rule

10-year shelf life rule

Post by baDBo » Sat, 16 Jun 2001 01:20:49



I noticed in NFPA 1127, rule 3-4.5, that the manufacturer should put a "use
before" date on any HPR motor with an expected shelf-life of less than 10-years
(I hope that this is also in NFPA 1125).  Anyone ever seen a "use before" date?

Should one infer from this, that if the motor doesn't have a "use before" date
that the manufacturer expects its shelf life to be more than 10-years?

Also, rule 3-4.4 drives a manufacturer to redesign a motor that deviates from
the sample test criteria and performance limits within 5-years.  Why isn't the
TRA/NAR certification life this same 5 years?  If the motor hasn't deteriorated
in 5-years, does NFPA give it an unlimited life or only another 5 years?

Any thoughts?

Bob

 
 
 

10-year shelf life rule

Post by Jerry Irvi » Sat, 16 Jun 2001 03:01:24



Quote:

> I noticed in NFPA 1127, rule 3-4.5, that the manufacturer should put a "use
> before" date on any HPR motor with an expected shelf-life of less than
10-years
> (I hope that this is also in NFPA 1125).  Anyone ever seen a "use

before" date?

Yes.  Composite Dynamics used to have a 3 year use before date due to
known delay aging issues (pre-kline) and even put a disclaimer on all
labels.  Yes they actually had labels.

Quote:

> Should one infer from this, that if the motor doesn't have a "use before" date
> that the manufacturer expects its shelf life to be more than 10-years?

Yes as it is universally true.

Quote:

> Also, rule 3-4.4 drives a manufacturer to redesign a motor that deviates from
> the sample test criteria and performance limits within 5-years.  Why isn't the
> TRA/NAR certification life this same 5 years?  If the motor hasn't
deteriorated
> in 5-years, does NFPA give it an unlimited life or only another 5 years?

> Any thoughts?

Arbitrary rules

TRA ignores rules generally.

Quote:

> Bob

Were you expecting a different answer?

--
Jerry Irvine, Box 1242, Claremont, California USA

Bring common sense back to rocketry administration.

 
 
 

10-year shelf life rule

Post by baDBo » Sat, 16 Jun 2001 03:54:39


Actually, yes.   After reading some of the discussions here on rmr, I thought
that there would be some logical, technical explanation of why TRA/NAR use 3
years instead of 5.  I don't know, something like small gremlins hatch in the
APCP after 3 years and begin eating the AP so that the motor no longer performs
up to specs. ;-)  You know something logical.

Perhaps, there was even a political motive behind the 3 year choice.  Or maybe a
personal one to get free motors (skim them from the test lot).  SOMETHING.  

If it was arbitrary, I would have thought that the manufacturers would have been
petitioning NAR/TRA long ago to change the 3 year rule and reduce costs and/or
decert worries.

Bob

Quote:



>> Also, rule 3-4.4 drives a manufacturer to redesign a motor that deviates from
>> the sample test criteria and performance limits within 5-years.  Why isn't the
>> TRA/NAR certification life this same 5 years?  If the motor hasn't
>deteriorated
>> in 5-years, does NFPA give it an unlimited life or only another 5 years?

>> Any thoughts?

>Arbitrary rules

>TRA ignores rules generally.

>Were you expecting a different answer?

 
 
 

10-year shelf life rule

Post by Jerry Irvi » Sat, 16 Jun 2001 07:49:27



Quote:

> Actually, yes.   After reading some of the discussions here on rmr, I thought
> that there would be some logical, technical explanation of why TRA/NAR use 3
> years instead of 5.  I don't know, something like small gremlins hatch in the
> APCP after 3 years and begin eating the AP so that the motor no longer
performs
> up to specs. ;-)  You know something logical.

> Perhaps, there was even a political motive behind the 3 year choice.  Or
maybe a
> personal one to get free motors (skim them from the test lot).  SOMETHING.  

> If it was arbitrary, I would have thought that the manufacturers would
have been
> petitioning NAR/TRA long ago to change the 3 year rule and reduce costs and/or
> decert worries.

I believe the 3 year rule was a compromise from the rule-loving weenies
who wanted annual testing.  Also purely arbitrary and overkill.

Permanant approvals are technically justified so long as any change in
motor design warrants a new test or perhaps even m y proposal of approving
entire lines of motors with a representative sample of motors.

Jerry

- Show quoted text -

Quote:

> Bob




> >> Also, rule 3-4.4 drives a manufacturer to redesign a motor that
deviates from
> >> the sample test criteria and performance limits within 5-years.  Why
isn't the
> >> TRA/NAR certification life this same 5 years?  If the motor hasn't
> >deteriorated
> >> in 5-years, does NFPA give it an unlimited life or only another 5 years?

> >> Any thoughts?

> >Arbitrary rules

> >TRA ignores rules generally.

> >Were you expecting a different answer?

--
Jerry Irvine, Box 1242, Claremont, California USA

Bring common sense back to rocketry administration.
 
 
 

10-year shelf life rule

Post by Dickinson' » Sat, 16 Jun 2001 09:57:47


I may be off base but doesn't the military still use hardware from the
Korean war era? I assume that the armament does not "expire"?
Just my $.02
Mike***inson


.

Quote:


> > Actually, yes.   After reading some of the discussions here on rmr, I
thought
> > that there would be some logical, technical explanation of why TRA/NAR
use 3
> > years instead of 5.  I don't know, something like small gremlins hatch
in the
> > APCP after 3 years and begin eating the AP so that the motor no longer
> performs
> > up to specs. ;-)  You know something logical.

> > Perhaps, there was even a political motive behind the 3 year choice.  Or
> maybe a
> > personal one to get free motors (skim them from the test lot).
SOMETHING.

> > If it was arbitrary, I would have thought that the manufacturers would
> have been
> > petitioning NAR/TRA long ago to change the 3 year rule and reduce costs
and/or
> > decert worries.

> I believe the 3 year rule was a compromise from the rule-loving weenies
> who wanted annual testing.  Also purely arbitrary and overkill.

> Permanant approvals are technically justified so long as any change in
> motor design warrants a new test or perhaps even m y proposal of approving
> entire lines of motors with a representative sample of motors.

> Jerry

> > Bob




> > >> Also, rule 3-4.4 drives a manufacturer to redesign a motor that
> deviates from
> > >> the sample test criteria and performance limits within 5-years.  Why
> isn't the
> > >> TRA/NAR certification life this same 5 years?  If the motor hasn't
> > >deteriorated
> > >> in 5-years, does NFPA give it an unlimited life or only another 5
years?

> > >> Any thoughts?

> > >Arbitrary rules

> > >TRA ignores rules generally.

> > >Were you expecting a different answer?

> --
> Jerry Irvine, Box 1242, Claremont, California USA

> Bring common sense back to rocketry administration.

 
 
 

10-year shelf life rule

Post by Kevin Trojanowsk » Sat, 16 Jun 2001 11:12:38


Remember the explosion on the USS Iowa?  The gunpowder bags used to fire
the rounds were one of the principal areas of investigation; apparently,
due to their age, they were a possibly a little more sensitive.

-Kevin

Quote:

> I may be off base but doesn't the military still use hardware from the
> Korean war era? I assume that the armament does not "expire"?
> Just my $.02
> Mike***inson



> .


> > > Actually, yes.   After reading some of the discussions here on rmr, I
> thought
> > > that there would be some logical, technical explanation of why TRA/NAR
> use 3
> > > years instead of 5.  I don't know, something like small gremlins hatch
> in the
> > > APCP after 3 years and begin eating the AP so that the motor no longer
> > performs
> > > up to specs. ;-)  You know something logical.

> > > Perhaps, there was even a political motive behind the 3 year choice.  Or
> > maybe a
> > > personal one to get free motors (skim them from the test lot).
> SOMETHING.

> > > If it was arbitrary, I would have thought that the manufacturers would
> > have been
> > > petitioning NAR/TRA long ago to change the 3 year rule and reduce costs
> and/or
> > > decert worries.

> > I believe the 3 year rule was a compromise from the rule-loving weenies
> > who wanted annual testing.  Also purely arbitrary and overkill.

> > Permanant approvals are technically justified so long as any change in
> > motor design warrants a new test or perhaps even m y proposal of approving
> > entire lines of motors with a representative sample of motors.

> > Jerry

> > > Bob




> > > >> Also, rule 3-4.4 drives a manufacturer to redesign a motor that
> > deviates from
> > > >> the sample test criteria and performance limits within 5-years.  Why
> > isn't the
> > > >> TRA/NAR certification life this same 5 years?  If the motor hasn't
> > > >deteriorated
> > > >> in 5-years, does NFPA give it an unlimited life or only another 5
> years?

> > > >> Any thoughts?

> > > >Arbitrary rules

> > > >TRA ignores rules generally.

> > > >Were you expecting a different answer?

> > --
> > Jerry Irvine, Box 1242, Claremont, California USA

> > Bring common sense back to rocketry administration.

 
 
 

10-year shelf life rule

Post by Doug Marr » Sat, 16 Jun 2001 18:33:31


Age was far less important than the fact they had been stored in a non
temp controlled environment near a river, where it regularly got up to
120 deg in the warehouse., then below zero in the winter. This level
oof temp cycle can make propellants extremely variable in
characteristics.
On Thu, 14 Jun 2001 21:12:38 -0500, Kevin Trojanowski

Quote:

>Remember the explosion on the USS Iowa?  The gunpowder bags used to fire
>the rounds were one of the principal areas of investigation; apparently,
>due to their age, they were a possibly a little more sensitive.

>-Kevin


>> I may be off base but doesn't the military still use hardware from the
>> Korean war era? I assume that the armament does not "expire"?
>> Just my $.02
>> Mike***inson



>> .


>> > > Actually, yes.   After reading some of the discussions here on rmr, I
>> thought
>> > > that there would be some logical, technical explanation of why TRA/NAR
>> use 3
>> > > years instead of 5.  I don't know, something like small gremlins hatch
>> in the
>> > > APCP after 3 years and begin eating the AP so that the motor no longer
>> > performs
>> > > up to specs. ;-)  You know something logical.

>> > > Perhaps, there was even a political motive behind the 3 year choice.  Or
>> > maybe a
>> > > personal one to get free motors (skim them from the test lot).
>> SOMETHING.

>> > > If it was arbitrary, I would have thought that the manufacturers would
>> > have been
>> > > petitioning NAR/TRA long ago to change the 3 year rule and reduce costs
>> and/or
>> > > decert worries.

>> > I believe the 3 year rule was a compromise from the rule-loving weenies
>> > who wanted annual testing.  Also purely arbitrary and overkill.

>> > Permanant approvals are technically justified so long as any change in
>> > motor design warrants a new test or perhaps even m y proposal of approving
>> > entire lines of motors with a representative sample of motors.

>> > Jerry

>> > > Bob




>> > > >> Also, rule 3-4.4 drives a manufacturer to redesign a motor that
>> > deviates from
>> > > >> the sample test criteria and performance limits within 5-years.  Why
>> > isn't the
>> > > >> TRA/NAR certification life this same 5 years?  If the motor hasn't
>> > > >deteriorated
>> > > >> in 5-years, does NFPA give it an unlimited life or only another 5
>> years?

>> > > >> Any thoughts?

>> > > >Arbitrary rules

>> > > >TRA ignores rules generally.

>> > > >Were you expecting a different answer?

>> > --
>> > Jerry Irvine, Box 1242, Claremont, California USA

>> > Bring common sense back to rocketry administration.

 
 
 

10-year shelf life rule

Post by Bob Bernatch » Sun, 17 Jun 2001 01:22:59


Quote:

> Remember the explosion on the USS Iowa?  The gunpowder bags used to fire
> the rounds were one of the principal areas of investigation; apparently,
> due to their age, they were a possibly a little more sensitive.

> -Kevin

IIRC, that was the reason given for the retirement of the SRAM missile
some years back.  They got severely temperature cycled sitting on the
plains of the Dakotas.  Maybe Chas Russell can offer more info on
this.

Regards,

Bob Bernatchez
NAR 29996

 
 
 

10-year shelf life rule

Post by Kevin Trojanowsk » Sun, 17 Jun 2001 07:15:50


Sounds similar to hauling motors out to the range to fly 'em in
Nebraska...
Quote:

> Age was far less important than the fact they had been stored in a non
> temp controlled environment near a river, where it regularly got up to
> 120 deg in the warehouse., then below zero in the winter. This level
> oof temp cycle can make propellants extremely variable in
> characteristics.